2.1 State Contingency Plan
...of a variety of waste, accidentally spilled substances, abandoned materials, soil, groundwater, surface water, air, and leaking underground tanks may be addressed through the Hawai`i ...
 

2.3 Emergency Response
...functioning vessel engine are exempt) Any free product that appears on groundwater Any amount of oil greater than 25 gallons released to the environment Any amount of ...
 

2.4 Environmental Cleanups
...cases complex environmental cleanups involving multiple contaminants and both soil and groundwater contamination can involve years of effort before the site is adequately cleaned up and closed. ...
 
...soils are discovered and removed during an emergency response, but some sub-soil or groundwater contamination still remains Groundwater contamination discovered in a non-drinking ...
 
...contamination still remains Groundwater contamination discovered in a non-drinking groundwater aquifer located below a former gasoline ...
 
...contamination discovered in a non-drinking groundwater aquifer located below a former gasoline service station A Phase II Environmental ...
 
...II Environmental Site Assessment required by a financial institution reveals soil or groundwater contaminated with a hazardous substance above HEER Office Environmental Action Levels ...
 
...they have typically aged, weathered, absorbed, or dispersed into the soil, or diluted in groundwater to the point that the contamination present does not pose a significant short-term hazard. ...
 
...soil staining or sampling data indicated the potential for remaining subsurface or groundwater contamination An overview of the discovery, assessment, and cleanup steps for non-emergency ...
 
...releases are usually identified when environmental samples (typically soil and/or groundwater) are collected at a site, and sample analysis shows Tier 1 EAL exceedances. These exceedances ...
 
...hazardous substance releases, including actual or probable releases to: Groundwater that is a drinking water supply Surface water that is a drinking water supply Groundwater ...
 
...that is a drinking water supply Surface water that is a drinking water supply Groundwater or surface water that is not a drinking water supply Air that poses a threat to public health ...
 
...substances, such as leaking containers or impoundments Soil, soil gas, indoor air, groundwater, or surface water that has contamination levels exceeding HDOH Tier 1 EALs Adverse ...
 
...The goal of a site assessment is to identify and remediate contaminated soil and groundwater that poses unacceptable environmental hazards, either under current site conditions or ...
 
...The investigation is carried out by the collection and analysis of samples of soil, groundwater, soil gas, surface water, sediment, air and/or other media as needed (see Sections 4 through ...
 
...or absence of potential hazards may simply be identified and the contaminated soil or groundwater quickly remediated without further assessment. In cases where remedial costs could be significant ...
 
...Section 13 and Evaluation of Environmental Hazards at Sites with Contaminated Soil and Groundwater, ">HDOH, 2008). This will help make the final EHE more site-specific and ensure that ...
 
... Cause of release or threat Site history General site geology, hydrology, groundwater status, adjacent land uses Distance to surface water bodies Situation preceding decision ...
 

2.5 Site Closure
...address contamination that may remain at the site (e.g., in the subsurface soil or groundwater). In these instances, the NFA letter will indicate that the emergency response has been appropriately ...
 
...Office guidance for Long-Term Management of Petroleum-Contaminated Soil and Groundwater, responsible parties may request the HEER Office to issue a determination that "No Further ...
 

3.0 Site Investigation Design And Implementation
... as needed. For example, detection of high levels of tetrachloroethylene in groundwater during a site investigation could suggest vapor intrusion as a potential environmental ...
 
...investigation could suggest vapor intrusion as a potential environmental hazard (e.g., groundwater action level for vapor intrusion exceeded). This could trigger the collection of soil gas samples ...
 

3.1 Site Investigation Scoping
...up on Phase I findings through the collection, analysis and evaluation of soil, groundwater, soil gas or other types of environmental samples (e.g., lead and asbestos testing of building ...
 
... maps and area-wide descriptions of geology, soil types, topography, and groundwater conditions); Historical use sources (e.g., aerial photographs, ...
 

3.2 Systematic Planning Of Site Investigation
...progression of environmental investigations at sites with contaminated soil and groundwater. Preparing DQOs prior to the initiation of field activities should ...
 
... Do preliminary data indicate the presence of contaminants in soil, groundwater or other environmental media greater than the HDOH Tier 1 Environmental Action Levels ...
 
...environmental hazards at a site (e.g., direct exposure, vapor intrusion, leaching to groundwater, etc.). The site investigation must be designed to meet this objective, as well as to provide ...
 
...exposure risk to residents? Is the size of the benzene plume in groundwater increasing, stable or shrinking? Does the contamination at the site extend ...
 
...presence of debris or fill material, location of utilities, depth to and use of groundwater, location and types of other manmade structures, etc. Identify nearby water supply wells, ...
 
...found in Evaluation of Environmental Hazards at Sites with Contaminated Soil and Groundwater (HDOH, 2011). Step 3—Identify Data Needs ...
 
... What types of media should be collected and analyzed (e.g., soil, soil gas, groundwater, surface water, etc.) based on areas and types of potential contamination? ...
 
...etc.) based on areas and types of potential contamination? For groundwater, how often will sampling need to be repeated, and how will samples for specific contaminants ...
 
...of soil gas samples. Concurrent collection of groundwater data should be considered at sites where soils are grossly contaminated with highly mobile ...
 
...or the type of contaminants present could otherwise pose significant leaching and groundwater contamination hazards (e.g., herbicides, such as atrazine). In other cases, additional ...
 
... Collection of soil gas data at sites where initial soil and/or groundwater data indicate potential vapor intrusion hazards. Analysis of soil samples that exceed ...
 
...the target contaminant is highly leachable from the soil and could pose a threat to groundwater resources or is highly volatile and could pose potential vapor intrusion hazards for buildings ...
 
...the driving environmental hazard is often direct exposure, rather than leaching and groundwater protection (e.g., arsenic, lead, PCBs, polychlorinated dibenzodioxins and polychlorinated ...
 
... Section 5. Issues to consider in developing the SAP for soil, groundwater, soil gas and other targeted media include: How can sample collection ...
 
... what is the minimal well size needed to collect the necessary amount of groundwater for sample analyses, given the site geology (e.g., micro-wells may not allow the ...
 
...sample collection methods are discussed in Sections 4 and 5. The collection of groundwater samples is discussed in Section 6. Soil gas and indoor air sampling is discussed ...
 
...testing) on the samples to better evaluate contaminant mobility and the threat to groundwater. These possible outcomes should be identified in advance under Step 3 and contingencies ...
 
...field staff at the anticipated or potential concentrations in soil, soil gas and groundwater? What physical site conditions could pose hazards to field staff and what ...
 
... A summary of common environmental hazards posed by contaminated soil and groundwater is provided in Figure 3-5. Site investigations and Environmental Hazard Evaluations ...
 
...to evaluate contaminant mobility (HDOH, 2007, 2011) and/or the collection of groundwater data (Section 6)? Do reported concentrations of COPCs in soil or groundwater ...
 
...data (Section 6)? Do reported concentrations of COPCs in soil or groundwater data present potential vapor intrusion concerns, indicating the need for soil gas or ...
 
... excavation activities? Do high levels of contaminants in groundwater indicate potential impacts to nearby aquatic habitats, suggesting the need to collect ...
 
...impacts to nearby aquatic habitats, suggesting the need to collect additional groundwater, sediment or surface water data? Do high levels of COPCs in soil and groundwater ...
 
...sediment or surface water data? Do high levels of COPCs in soil and groundwater pose a threat to offsite migration which could lead to contamination of adjacent properties? ...
 

3.3 Conceptual Site Models
...of common environmental hazards associated with contaminated soil and groundwater as well as potential exposure pathways for human and ecological receptors. ...
 
...a pictorial depiction of environmental hazards associated with contaminated soil and groundwater (see also Figure 3-5). Exposure pathways to human and ecological receptors are also indicated ...
 
...this includes a summary of the known or suspected extent and magnitude of soil and groundwater contamination. In addition, site conditions such as land use, groundwater use, potential ...
 
...contamination. In addition, site conditions such as land use, groundwater use, potential onsite and offsite receptors, exposure or isolation of contaminated soil, ...
 
...posed by the COPC. Common environmental hazards associated with contaminated soil and groundwater (Figures 3-5 and 3-6) include: Contaminated Soil: ...
 
...vapors to building interiors; Leaching and contamination of groundwater resources; Impacts to terrestrial habitats (terrestrial ...
 
...odors, general resource degradation, etc.); Contaminated Groundwater: Contamination of drinking water resources (toxicity, taste ...
 
...subsurface vapors to building interiors; Discharges of contaminated groundwater to surface water aquatic habitats (aquatic ecotoxicity or gross contamination conditions); ...
 
...document Evaluation of Environmental Hazards at Sites with Contaminated Soil and Groundwater (HDOH, 2011). These environmental hazards form the basis of the ...
 
...Four default CSMs or site scenarios are provided for in the Tier 1 EALs, depending on groundwater utility and location of a subject site with respect to nearby surface water bodies ...
 
...(see Section 13). Only surface water bodies that are hydraulically connected to groundwater are considered to be potentially threatened by contaminated groundwater. This could include ...
 
...are considered to be potentially threatened by contaminated groundwater. This could include streams, drainage ways, or even leaky storm sewers that lead to a surface ...
 
...to aquatic habitats, storm sewers in direct hydraulic connection with contaminated groundwater are considered to represent a "surface water body" for initial screening purposes. Measuring ...
 
...body" for initial screening purposes. Measuring the piping invert in relation to the groundwater table at high-high tides and the presence or absence of free product at the discharge ...
 
...could be significant, or at sites where long-term management of contaminated soil or groundwater will be required. A closer evaluation of current and future risks to human or ecological ...
 
... site boundaries; Area of contaminated soil is paved; Underlying groundwater is not a current or potential source of drinking water; Site is located ...
 
...that the pathway for leaching of contaminants from soil and contamination of groundwater is complete, because contaminated soil is in direct contact with groundwater, even though ...
 
...is complete, because contaminated soil is in direct contact with groundwater, even though the area is assumed to be capped with pavement. This is used to support the ...
 
...area is assumed to be capped with pavement. This is used to support the collection of groundwater data to more directly evaluate impacts and potential concerns. Removal of pavement could ...
 
...and potential concerns. Removal of pavement could also exacerbate leaching and groundwater contamination due to infiltrating rain or irrigation water. This could require the maintenance ...
 
... The more detailed CSM may be used to support a conclusion that contaminated soil and groundwater does not pose unacceptable environmental hazards under current site conditions. Depending ...
 
...area of contaminated soil remain capped, that a health and safety plan and soil and groundwater management measures be developed prior to any subsurface construction activities at the ...
 
... construction activities at the site, and that the need for long-term monitoring of groundwater be further evaluated. Actions related to restricted-use site closure, and the preparation ...
 
...potential environmental hazards, including leaching and potential contamination of groundwater (refer to Figure 3-5; see also Section 13). As discussed in Sections 2, 3 ...
 
... (along with other relevant information): Additional soil, soil vapor or groundwater data; Location of existing monitoring wells and past ...
 
...(preferably based on decision unit and Multi Increment sample data); Groundwater contamination summary figures with areas above EALs highlighted; Soil ...
 
...summary figures with areas above EALs highlighted; Direction of groundwater flow, depth to groundwater; Cross sections that depict the site ...
 
...flow, depth to groundwater; Cross sections that depict the site stratigraphy as well as the lateral ...
 

3.4 Selection Of Decision Units
...document Evaluation of Environmental Hazards at Sites with Contaminated Soil and Groundwater (HDOH, 2011). 3.4.1 DECISION UNIT DESIGNATION ...
 
...should be selected to characterize the area. DUs for different media (e.g. soil vs. groundwater vs. soil gas vs. indoor air) should in most cases be treated separately, even if they are ...
 
...multiple environmental hazards, including leaching of contamination to subsurface groundwater resources, intrusion of vapors into overlying buildings and nuisance or even explosion ...
 
...or other chemicals that could migrate downwards and contaminate deeper soil or groundwater. A subsurface investigation may also be required to further delineate contamination documented ...
 
...chemicals (e.g. explosives residues) can also pose potential leaching threats to groundwater that might be used to serve the redevelopment in the future. A default ...
 
...guidance Evaluation of Environmental Hazards at Sites with Contaminated Soil and Groundwater (HDOH, 2011). When using a Decision Unit strategy, the entire area of a Decision Unit is ...
 

3.5 Example Decision Units
...from approximately 1,000 ft2 to 2,000 ft2. These areas primarily pose leaching and groundwater impact hazards. Subsurface DU layers designated for the site are ...
 
...water during rain events, as well as leaching of salt and impacts to underlying groundwater. (Note that while a high sodium content can inhibit leaching and runoff, this will also ...
 

3.6 Sampling And Analysis Plans
... Section 4.3). See Section 6 for sample collection strategies for groundwater, and Section 13 for information and references regarding ecological risk evaluations. ...
 
...be useful for a given site. Sampling method procedural guidance for soil and sediment, groundwater and surface water, and soil vapor and indoor air is presented in Sections 5, ...
 

3.8 Data Quality Assessment
...if sampling did not delineate the vertical or horizontal extent of contamination, or if groundwater was not encountered due to drilling refusal at a site where groundwater was believed ...
 
... was not encountered due to drilling refusal at a site where groundwater was believed to be impacted; then additional sampling would typically be required. ...
 

3.9 Site Investigation Reports
...18. The HEER Office requires that the lateral and, as needed, vertical extent of soil and groundwater (and in some cases soil gas) contamination be clearly depicted on to-scale maps and cross sections ...
 

3.10 Environmental Hazard Evaluation
...HDOH document Evaluation of Environmental Hazards at Sites with Contaminated Soil and Groundwater (HDOH, 2011). An overview of the document is provided in Section 13. As ...
 
...to identifying potential environmental hazards associated with contaminated soil or groundwater is a direct comparison of site data to the HDOH Tier 1 EALs (see Section 13). ...
 
... of a COPC exceeds the Tier 1 EAL in the subject media (e.g., soil, soil gas, or groundwater) then the specific environmental hazard(s) potentially posed by the chemical should be identified ...
 
...of potential leaching hazards associated with a COPC suggests that batch testing and/or groundwater data may be needed. The identification of potential vapor intrusion concerns suggests that ...
 

4.2 Use Of Multi Increment Samples To Characterize DUs
...soil should normally be accompanied by the concurrent or followup collection of groundwater (Section 6) and/or soil vapor samples (see Section 7). Volatile chemicals ...
 
...intrusion hazards. These concerns can be more directly addressed through testing of groundwater and soil vapors. 4.2.4 INCREMENT DISTRIBUTION ...
 
...with diesel and other middle distillate fuels is no longer required (tested for groundwater only; refer to Section 9). Note also that naphthalene can be reported under most VOC ...
 
... potential vapor intrusion hazards associated with volatile contaminants in soil (and groundwater). Soil gas data are also very useful for identifying and locating areas of heavy contamination. ...
 
...document Evaluation of Environmental Hazards at Sites with Contaminated Soil and Groundwater (HDOH, 2011) and Section 7 of this TGM for additional information. ...
 
...leachable contaminants are found in surface soils above HDOH EALs; Groundwater data suggest that a release has occurred and contamination has migrated through the ...
 
...example the collection of soil gas samples for volatile contaminants or testing of groundwater for contaminants that pose potential leaching hazards. Sampling constraints and potential ...
 

5.1 Initial Site Inspection
... likely to be encountered in the subsurface, as well as the anticipated depth to groundwater. Direct push rigs are preferable for the collection of continuous cores and subsurface Multi ...
 

5.4 Subsurface Soil Sample Collection
...ideal for MI sampling strategies. Push rigs can also be used to collect soil gas or groundwater samples. Soil gas sampling is discussed in Section 7. The use of push rigs ...
 
...in Section 7. The use of push rigs to install small-diameter monitoring wells for groundwater collection is discussed in Section 6.2. Smaller track-mounted rigs could be ...
 

5.8 Field Documentation
...vesicles in either lava type. All of these may indicate preferential pathways for groundwater travel. Tuff (T) � Descriptions of tuff should include boring ...
 
...of rock type should pay primary attention to characteristics that potentially affect groundwater behavior (e.g. basalt fracturing, carbonate porosity). An example rock description is as ...
 

6.0 Groundwater and Surface Water Sampling Guidance
... ' SECTION 6 GROUNDWATER AND SURFACE WATER SAMPLING GUIDANCE Interim Final-December 31, 2008 ...
 

Contents
... 6.0 Groundwater and Surface Water Sampling Guidance ...
 
... 6.1 Groundwater Monitoring Well Placement   ...
 
... 6.1.1 Initial Groundwater Investigation Phase   ...
 
... 6.3 Groundwater Gauging   ...
 
... 6.5 Groundwater Sample Collection Methods   ...
 
... 6.5.7 Order of Groundwater Sampling   ...
 
... 6.6 Filtration of Groundwater Samples   ...
 
... 6.8 Groundwater Modeling   ...
 
... 6-1 Diagram of a Typical Groundwater Monitoring Well   ...
 
... 6-11 Example Groundwater Sampling Log   ...
 
... 6-15 Bailers for Purging and Groundwater Sampling   ...
 
... Potential for Representative Analytical Results for commonly Utilized Groundwater Sampling Methods for Common Contaminants of Potential Concern ...
 

6.0 Groundwater and Surface Water Sampling Guidance
... ' 6.0 GROUNDWATER AND SURFACE WATER SAMPLING GUIDANCE The sampling guidelines presented in this section ...
 
...part of an environmental investigation are representative of the in-situ condition of the groundwater or surface water, and that data derived from these samples can be used for decision making ...
 
...sampling, as well as an overview of sampling equipment available for the collection of groundwater or surface water samples. This section refers to information in other TGM sections ...
 
... This section refers to information in other TGM sections that are relevant to groundwater and surface water sampling. For instance, site investigations may sometimes feature ...
 
... and surface water sampling. For instance, site investigations may sometimes feature groundwater as the sole media of concern, but groundwater sample collection is most frequently performed ...
 
...as the sole media of concern, but groundwater sample collection is most frequently performed as part of a larger investigation that also ...
 

Figures
... 6-1 Diagram of a Typical Groundwater Monitoring Well   ...
 
... 6-11 Example Groundwater Sampling Log   ...
 
... 6-15 Bailers for Purging and Groundwater Sampling   ...
 

Tables
... Potential for Representative Analytical Results for commonly Utilized Groundwater Sampling Methods for Common Contaminants of Potential Concern ...
 

6.1 Groundwater Monitoring Well Placement
... ' 6.1 GROUNDWATER MONITORING WELL PLACEMENT The SAP must identify the site-specific monitoring well design ...
 
...Section 3) that describe the site topography, the geologic setting, and the presumed groundwater hydrology The area of environmental concern The contaminants of potential concern ...
 
...as potable water supply wells, irrigation wells, and surface streams connected to groundwater Influences on hydrology such as injection wells or tidal fluctuation ...
 
...on hydrology such as injection wells or tidal fluctuation 6.1.1 Initial Groundwater Investigation Phase The initial investigation phase described in this section assumes ...
 
...conditions: (1) a single point source or area of suspected contamination, and (2) prior groundwater investigation has not been conducted. The preliminary conceptual model (see ...
 
...from published reports such as the Aquifer Identification and Classification Reports: Groundwater Protection Strategy for Hawai`i (Mink, J.F. and L.S. Lau, 1990a; 1990b; 1992; ...
 
...whether contaminants have impacted the uppermost water bearing zone including perched groundwater. During this phase, a minimum of three wells are required for each known or suspected contaminant ...
 
...angles relative to one another, will provide sufficient data to establish the local groundwater flow direction through static groundwater level measurements. Place at least ...
 
...flow direction through static groundwater level measurements. Place at least one of these wells in proximity to the source area ...
 
...the initial investigation phase, the well screens must extend across the water table and groundwater sampling must include the uppermost water bearing zone, including perched groundwater. Monitoring ...
 
...sampling must include the uppermost water bearing zone, including perched groundwater. Monitoring wells with screens extending across the water table are typically installed with ...
 
...and 3 feet of screen interval above the water table. This allows for the assessment of groundwater level fluctuations as well as the accumulation of free product on the water table surface. ...
 
... wells may be required to delineate the horizontal and/or vertical extent of the groundwater contamination plume. In general, contamination resulting from petroleum products (which are ...
 
...are denser than water, and sink). To delineate the horizontal extent of groundwater impacts, monitoring wells are installed cross gradient, up gradient, and down gradient of the ...
 
...important if one or more contaminants of concern occur naturally in the soil and groundwater at the site. To delineate the vertical extent of groundwater impacts, monitoring wells ...
 
...at the site. To delineate the vertical extent of groundwater impacts, monitoring wells are installed with successively deeper screen intervals. Screen intervals ...
 
...of any confining units between upper and lower aquifers to prevent the vertical spread of groundwater contamination. When possible, drill to and collect geotechnical samples from the confining ...
 

6.2 Monitoring Well Installation and Abandonment
... determination of the potential presence, extent, and movement of contaminant plumes in groundwater, as well as the assessment of aquifer characteristics (for use in groundwater models). Monitoring ...
 
...as well as the assessment of aquifer characteristics (for use in groundwater models). Monitoring wells must therefore facilitate hydrologic testing and facilitate the collection ...
 
...therefore facilitate hydrologic testing and facilitate the collection of representative groundwater samples. There is no "typical" monitoring well for achieving this objective. ...
 
...construction and materials are a function of the anticipated nature of the contaminants, groundwater quality, desired sampling depth(s), the aquifer's lithology and its overburden, the borehole ...
 
...a shallow or smaller diameter well. To ensure that samples are representative of groundwater conditions, monitoring well design should reflect anticipated contaminant properties. For example, ...
 
...bearing units. 6.2.1 Permanent Monitoring Wells All permanent groundwater monitoring wells have certain design components in common (USEPA, 1991a). A schematic of a ...
 
...wells have certain design components in common (USEPA, 1991a). A schematic of a standard groundwater monitoring well is presented in Figure 6-1. The monitoring well design components ...
 
...protection Figure 6-1. Diagram of a Typical Groundwater Monitoring Well This illustration shows the screen interval across the water table, ...
 
...solid well riser and a well screen, which keeps the borehole open and provides access to groundwater for the collection of a water sample. The casing should always include a bottom cap to exclude ...
 
... depending on the objective of the well installation (e.g., site investigation or groundwater remediation) and the proposed monitoring and test equipment. When practical, the casing diameter ...
 
...exceed 4 inches to avoid generating large volumes of potentially contaminated soil and groundwater requiring management and disposal during well installation, development and purging activities. ...
 
...(USEPA, 1991a; CalEPA, 1995b). The casing material must not alter the groundwater chemistry by leaching, sorbing or desorbing It must be strong enough to withstand ...
 
...consisting of clean silica sand is installed around the well screen and allows groundwater to flow into the monitoring well for the collection of groundwater samples. ...
 
...to flow into the monitoring well for the collection of groundwater samples. Figure 6-3. Hollow Stem Auger with PVC ...
 
... (ASTM, 2004a). Handbook of Suggested Practices for the Design and Installation of Groundwater-Monitoring Wells (USEPA, 1991a). Test Methods for Evaluating Solid Waste, Volume ...
 
...the filter pack material (USEPA, 1991a). For typical investigations of shallow groundwater in Hawai`i, a 2-inch diameter PVC casing with a screen slot size of 0.020 inches combined ...
 
... and 3 feet of screen interval above the water table. This allows for the assessment of groundwater level fluctuations as well as the accumulation of free product on the water table surface. ...
 
...A solid riser below the screen may lead to stagnant environments, which may alter the groundwater chemistry (USACE, 1998). The total borehole depth should not be more than 1 ...
 
...below the planned bottom of the monitoring well in order to avoid preferential vertical groundwater flow originating from below the well screen. If a borehole extends greater than 1 meter ...
 
...of the well screen to 2 to 5 feet above the well screen, if feasible. In areas of shallow groundwater, a site-specific plan is recommended before installation of the wells begins. The filter pack ...
 
...bentonite seal, if feasible, is installed above the filter pack. In areas of shallow groundwater, a site-specific plan is recommended before installation of the wells begins. Pelletized bentonite ...
 
... 6.2.1.6 Well Survey All wells being used to assess the hydraulic gradient and the groundwater flow direction must be surveyed by a licensed professional surveyor. Record the well locations ...
 
...pack, and adjacent formation such that the resulting inflow is representative of the groundwater flow in the surrounding aquifer. Final well development proceeds after well installation ...
 
...from the screen, filter pack and adjacent formation. Surging is alternated with groundwater pumping to remove groundwater and sediment accumulated in the well during surging. Use of ...
 
...pumping to remove groundwater and sediment accumulated in the well during surging. Use of a vented, rather than un-vented, ...
 
...particulates stuck in the well screen and filter pack. Backwashing is alternated with groundwater pumping to remove groundwater and the sediment suspended in the groundwater due to well development. ...
 
...pumping to remove groundwater and the sediment suspended in the groundwater due to well development. A combination of surging, ...
 
...and the sediment suspended in the groundwater due to well development. A combination of surging, backwashing, and pumping may be used to ...
 
...the well screen, filter pack and adjacent formation. Hydraulic jetting is alternated with groundwater pumping to remove groundwater and sediment accumulated in the well by jetting. ...
 
...pumping to remove groundwater and sediment accumulated in the well by jetting. When using water during drilling, ...
 
... per liter. The well water is clear to the unaided eye, in areas where the local groundwater is known to be clear and the turbidity readings are below 10 nephelometric turbidity ...
 
...±10 percent at concentrations larger than 10 NTU. In areas of known turbid groundwater, the final well water may be turbid to the eye. The sediment thickness in the ...
 
...log for each monitoring well. ASTM Standard D5521 (ASTM, 2005a) presents additional guidance on groundwater well development. An example well development log is illustrated on Figure 6-8. ...
 
...later than 7 days after well completion. The HEER Office recommends that groundwater gauging, purging and sampling be conducted no sooner than 14 days after well development. The ...
 
...Guidance from other agencies for the time interval between monitoring well completion and groundwater sample collection ranges from 24 hours (US Navy, 2007) to 48 hours (SC DHEC, 2005) to several ...
 
...2008.] 6.2.2 Temporary Monitoring Wells Temporary groundwater monitoring wells or sampling points are generally installed in boreholes driven by direct push ...
 
... according to the procedures outlined in Subsection 6.4. The use of temporary groundwater monitoring wells is not as rigorous as the construction and development of permanent groundwater ...
 
...monitoring wells is not as rigorous as the construction and development of permanent groundwater monitoring wells, and the samples collected may not be representative of the aquifer. However, ...
 
...a lower cost alternative to the initial characterization or delineation of potential groundwater impacts. While the use of temporary monitoring wells may be advantageous in some instances, ...
 
...may be advantageous in some instances, they are not suitable for long-term monitoring of groundwater or for final decision making purposes. The intended use of data collected from temporary monitoring ...
 
...with the HEER Office. 6.2.3 Other Wells Other wells used for groundwater sampling include micro wells, existing production wells and potable wells. The following sections ...
 
...Well Sampling Collection of water samples for analysis from wells other than groundwater monitoring wells should be approved by the HEER Office. The request should be accompanied by ...
 
...and depth, seal material and depth Elevation of screen interval Depth to groundwater table and bottom of unconfined aquifer Depth to top and bottom of confined aquifer(s) ...
 
... (before any treatment). Purge the well long enough to obtain a representative sample of groundwater with a minimal residence time in the collection/distribution system. The purge volume may be ...
 
...Permanent Downhole Equipment Dedicated sampling equipment that will reside within a groundwater monitoring well must not alter the chemistry of the groundwater and must be resistant to chemical ...
 
...monitoring well must not alter the chemistry of the groundwater and must be resistant to chemical or physical deterioration. Inspect the equipment periodically ...
 
...Wells at Sites with DNAPL Plumes Most DNAPLs that are commonly found in soil and groundwater contamination fall into four groups (USEPA, 2004c): Chlorinated solvents used ...
 
...manufactured gas plants (MGP) The tendency of DNAPLs to move independently of groundwater flow makes it difficult to delineate and remediate free phase DNAPL plumes. Most DNAPLs are ...
 
...DNAPLs with a high enough density, therefore, migrate vertically rather than following groundwater movement. In addition, they may migrate according to the slope of the uppermost confining unit, ...
 
...to the slope of the uppermost confining unit, which may differ from the regional groundwater flow direction. The migration of DNAPLs with a density (specific gravity) closer to ...
 
...migration of DNAPLs with a density (specific gravity) closer to 1 will be influenced by groundwater movement to a greater degree. The USEPA has published a guidance document that helps ...
 
...PCBs are not volatile and are not sufficiently soluble to be readily detectable in groundwater. The lighter end PCBs do have some solubility [3 milligram per liter (mg/L) range] and ...
 
...polynuclear aromatics are volatile and sufficiently soluble to be detected as a groundwater plume Coal tar creosote mixtures are very diverse and may or may not be associated with ...
 
... Coal tar creosote mixtures are very diverse and may or may not be associated with groundwater plumes. They may contain several chemicals that fluoresce The HEER Office requires ...
 
...that both the free phase and dissolved plumes are delineated at DNAPL sites. Borings and groundwater monitoring wells should be designed to accommodate the selected investigation techniques. ...
 
...has many consequences. For example, in a hydraulically isotropic, porous formation, the groundwater flow direction is perpendicular to the equipotential lines of the water table or potentiometric ...
 
...is to prevent surface water from infiltrating into the subsurface and to prevent vertical groundwater movement within the aquifer (HDLNR, 2004). By eliminating water movement vertically within ...
 
...to be a potential conduit for contaminant dispersion (USEPA, 1991a). A groundwater monitoring well that is no longer needed, sustains damage serious enough to potentially affect ...
 
...Office. 6.2.5.1 Well Abandonment Planning All soil borings and groundwater monitoring wells will eventually require decommissioning and closure in accordance with the ...
 
...depth. Pressure grout the borehole to within 5 feet of ground surface or to above the groundwater table, whichever is shallower (CalEPA, 1995b). Pressure grouting is described ...
 
...well casing. Pressure grout the well to within 5 feet of ground surface or to above the groundwater table whichever is shallower (CalEPA, 1995b). Pressure grouting is described ...
 
...Backfill with Clean Soil This option may be used only in areas where groundwater is not a current or potential source of drinking water or where contamination has not been ...
 
...depth Backfill the borehole to within 5 feet of ground surface or to above the groundwater table whichever is shallower The backfill must be composed of silty clay or clayey ...
 
...It is not recommended to use neat cement in the saturated zone, particularly if the groundwater is acidic. Water with an acidic pH may corrode the cement (USEPA, 1991a). The rationale ...
 
... when abandoning wells in locations where load-bearing is not a concern and where groundwater is encountered at a depth of less than 20 feet below ground surface. 6.2.5.5 Well ...
 

6.3 Groundwater Gauging
... ' 6.3 GROUNDWATER GAUGING The purpose of groundwater gauging is to construct a groundwater table map or ...
 
...GAUGING The purpose of groundwater gauging is to construct a groundwater table map or a potentiometric surface map for the site ...
 
...gauging is to construct a groundwater table map or a potentiometric surface map for the site under investigation. The data are used ...
 
...The data are used to calculate the hydraulic gradient(s) and the horizontal groundwater flow direction(s) across the site. Therefore, all measurements must be taken within a 24-hour ...
 
... the contaminants present. The HEER Office requires a minimum of two rounds of groundwater gauging to verify the groundwater gradient(s) and flow direction(s). The two gauging events ...
 
...gauging to verify the groundwater gradient(s) and flow direction(s). The two gauging events must be separated by a minimum of ...
 
... On sites that are tidally influenced, perform a tidal study to determine the net groundwater flow direction. If site investigation, monitoring and remedial efforts continue over a year, ...
 
...investigation, monitoring and remedial efforts continue over a year, include seasonal groundwater gauging into the investigation to determine the influence of seasonal variations in the aquifer. ...
 
...determine the influence of seasonal variations in the aquifer. Correct the measured groundwater elevations for tidal influences, barometric influences, and overlying free product thickness. ...
 
... 6.3.1 Monitoring Well Equilibration During well development, a large amount of groundwater is pulled through the surrounding formation as well as the filter pack and the well casing. ...
 
...casing. This may disturb the chemical equilibrium of the surrounding formation with the groundwater. In addition, the filter pack may not reach chemical equilibrium with the aquifer. ...
 
... down the aquifer adjacent to the well. The HEER Office recommends that groundwater gauging and sampling be conducted no sooner than 14 days after well development. However, equilibration ...
 
...for several minutes to document that the water level has equilibrated. If groundwater sampling is to be completed on the same day, measure the depth to water prior to sampling. ...
 
...measurement at least once to confirm the measurement (USEPA, 1999a). If groundwater sampling is to be completed on the same day, measure the total well depth after sampling has ...
 
... 6.3.5 Well Gauging Log At a minimum record the following information on groundwater monitoring logs: Date Project name and location Field personnel ...
 
... Time of measurement Depth to free product Depth to groundwater Depth to bottom of well Observations (casing condition, well head ...
 
... etc.) Activities that may influence water level (groundwater pumping, irrigation, etc.) Decontamination procedures ...
 
...Tidal sea level changes result in changes of hydraulic pressure at the shoreline, where groundwater flows into the ocean. As the tide rises, hydraulic pressure increases and causes backpressure ...
 
...study may be necessary at sites that are tidally influenced. Continually gauge and record groundwater elevations at the site for a minimum period of 72 hours. Gauge at least three monitoring wells ...
 
...less. Synchronize data logging between all pressure gauges. Calculate the groundwater gradient and flow direction for each sampling time. Calculate the net groundwater gradient ...
 
...gradient and flow direction for each sampling time. Calculate the net groundwater gradient and net flow direction. Compare the times of tidal fluctuations between the ...
 
...the ocean and each monitoring well to determine the tidal lag of each well. Compare the groundwater elevation changes within each well to the sea level changes to calculate the tidal efficiency ...
 
... within each well to the sea level changes to calculate the tidal efficiency (percent of groundwater elevation change compared to sea level change). On a map, present the groundwater flow ...
 
...elevation change compared to sea level change). On a map, present the groundwater flow directions as they change throughout one tidal cycle. Present the groundwater gradient ...
 
...flow directions as they change throughout one tidal cycle. Present the groundwater gradient for each flow direction. In addition, present the net groundwater flow direction and ...
 
...gradient for each flow direction. In addition, present the net groundwater flow direction and gradient on the same map. If variations are seen between tidal cycles, present ...
 
...cycle on a map. 6.3.6.2 Gauging at Tidally Influenced Sites Groundwater gauging at tidally influenced sites requires careful planning. Choose the date and time of ...
 
...every half an hour between gauging other wells. Assume that the change in groundwater elevation within the reference well is linear throughout the half hour between measurements. ...
 
... throughout the half hour between measurements. Use the linear regression of the groundwater elevation change in the reference well to correct the groundwater elevations for all wells ...
 
...elevation change in the reference well to correct the groundwater elevations for all wells for tidal influence. On sites with large variations in tidal efficiency ...
 
... choose more than one reference well. 6.3.7 Seasonal Effects Groundwater flow may exhibit significant seasonal variations between the dry season and the wet season ...
 
... and the wet season in Hawai`i. Characterizing seasonal and temporal variations in groundwater flow is important at sites where the groundwater flow direction may change due to seasonal ...
 
...flow is important at sites where the groundwater flow direction may change due to seasonal variations. It is also important for site investigations ...
 
...and seasonal variations, the following processes can introduce temporal variations in the groundwater table/potentiometric surface and possibly in the groundwater flow direction (USEPA, 1992d; ...
 
...table/potentiometric surface and possibly in the groundwater flow direction (USEPA, 1992d; CalEPA, 1995a): Barometric effects Variations ...
 
... Identify and evaluate factors that result in short- or long-term variations in groundwater elevations and flow patterns. Measure the water levels frequently enough to detect ...
 
...the water levels frequently enough to detect and characterize temporal variations in groundwater flow. 6.3.9 Determination of Vertical Hydraulic Gradient and Flow Direction ...
 
... Determine the vertical hydraulic gradient and flow direction on sites where vertical groundwater flow is significant. A deep vertical extent of a dissolved contaminant plume is an indication ...
 
...A deep vertical extent of a dissolved contaminant plume is an indication that vertical groundwater flow is significant. To determine the vertical component of groundwater flow, install ...
 
...flow is significant. To determine the vertical component of groundwater flow, install multiple piezometers or wells in clusters or nests, or multi-level wells or sampling ...
 
...horizontally, may produce imprecise information regarding the vertical component of groundwater flow Installation of multiple piezometers closely spaced or within ...
 
...document entitled "Handbook of Suggested Practices for the Design and Installation of Groundwater-Monitoring Wells" (USEPA, 1991a) for a discussion of the advantages and disadvantages of ...
 
...on site. The two or more measurement points must be aligned parallel to the horizontal groundwater flow direction. During groundwater gauging in the piezometers, follow the procedures ...
 
... flow direction. During groundwater gauging in the piezometers, follow the procedures for groundwater gauging detailed in Section ...
 
...gauging in the piezometers, follow the procedures for groundwater gauging detailed in Section 6.3. Calculate the vertical groundwater flow directions and ...
 
...gauging detailed in Section 6.3. Calculate the vertical groundwater flow directions and hydraulic gradient using the water level measurements. Generate a vertical ...
 

6.4 Purging
... ' 6.4 PURGING The purpose of well purging before groundwater sampling is to ensure that the samples will be representative of the groundwater and contaminant ...
 
...sampling is to ensure that the samples will be representative of the groundwater and contaminant levels in the vicinity of the well. If a well is left untended for prolonged ...
 
...through gas exchange with headspace, etc. Excessive purging may result in biased groundwater samples, since it may dilute or increase the contaminant concentrations at the sampling ...
 
...a purging device that will not alter the geochemical and physical parameters of the groundwater and dissolved contaminants or increase turbidity. Keep the contaminant characteristics in mind ...
 
...though due to the greater potential to alter geochemical and physical parameters of groundwater and other limitations, their use is generally limited to monitoring wells with specific characteristics ...
 
...water above the screen has been purged. It also ensures that during sampling, the groundwater has the shortest riser length to pass (USEPA, 2002b). If the intake is placed ...
 
...if a low-flow purging and sampling technique is used (USEPA, 2002b). All groundwater extracted from wells during purging must be properly containerized, staged, sampled, and disposed. ...
 
...plastic sheet to ensure that the ground around the well is not cross contaminated by groundwater, and to ensure that downhole equipment does not transfer surface materials into the well. ...
 
...purging and sampling approach be utilized whenever feasible to collect representative groundwater samples. The purpose of the low-flow purging is to sample a specific depth within a well ...
 
... per liter. Well water is clear to the unaided eye in areas where the local groundwater is known to be clear and the turbidity readings are below 10 NTUs. Turbidity ...
 
...±10 percent at concentrations larger than 10 NTU. In areas of known turbid groundwater, the final well water may be turbid to the eye. The HEER Office recommends ...
 
... The HEER Office recommends the use of flow-through cells when monitoring groundwater stabilization parameters during purging. Flow-through cells contain an inlet at the ...
 
... liters per minute (USEPA, 2002b). Alternatively, use a bailer to remove groundwater from the well. Start bailing near the water table and keep lowering the bailer as purging continues. ...
 
... to determine water quality parameters during purging. Figure 6-11 presents an example Groundwater Sampling Log containing locations for recording purging parameters prior to the collection ...
 
...Log containing locations for recording purging parameters prior to the collection of groundwater samples. Figure 6-11. Example Groundwater Sampling ...
 
...samples. Figure 6-11. Example Groundwater Sampling Log [Source: US Navy, 2007] ...
 

6.5 Groundwater Sample Collection Methods
... ' 6.5 GROUNDWATER SAMPLE COLLECTION METHODS The purpose of groundwater sampling is to collect samples representative ...
 
...SAMPLE COLLECTION METHODS The purpose of groundwater sampling is to collect samples representative for the aquifer at the well location. Consider ...
 
...of the contaminant(s) such as volatility, solubility, density (denser or lighter than groundwater) and their resultant fate in the subsurface (adhesion to soil particles, biodegradation ...
 
...of the sampling approach. The following sections describe different methods of groundwater sampling, the different types of equipment for each method, and details on the appropriate ...
 
...6-2 presents the potential for representative analytical results for commonly utilized groundwater sampling methods for common contaminants of potential concern. Table 6-2 ...
 
... Table 6-2 Potential for Representative Analytical Results for Commonly Utilized Groundwater Sampling Methods for Common Contaminants of Potential Concern ...
 
... Figure 6-14. Field Setup for Purging and Sampling Well Purging and sampling of groundwater monitoring well using a portable low-flow bladder pump driven by a portable air compressor ...
 
... Figure 6-15. Bailers for Purging and Groundwater Sampling The following representative bailers are shown: ...
 
...Low-Flow Sampling The purpose of low-flow sampling is to collect representative groundwater samples for a specific depth within a well screen interval. The method is based on the assumption ...
 
...sampling approach be utilized where appropriate and feasible to collect representative groundwater samples. Low-flow sampling is preceded by low-flow purging (see Subsection ...
 
...between purging and sampling. Keep the pump rate throughout sampling low enough that the groundwater flow exiting from the discharge tube is laminar and does not induce turbulence in sampling ...
 
...the site contaminants. Install a device that will prevent backflow to the pump to avoid groundwater contamination. Install the pump at a sufficient height above the bottom of the well to ...
 
... 6.4.3 Purging Low-Permeability Formations. Keep the pump rate low enough that the groundwater flow from the tube is laminar and does not induce turbulence in sampling containers. Choose ...
 
... tasks. The purpose of bailer sampling is to collect samples representative of the groundwater at the sampling point. Therefore, bailer sampling must be preceded by well purging. ...
 
...creating a vacuum in an intake line drawing from the monitoring well. The vacuum draws groundwater up to the pump, where the water is dispensed from the end of the tubing. Tubing used for peristaltic ...
 
... Office prior to field investigation. 6.5.6 Others Other groundwater samplers include passive diffusion samplers for VOCs or SVOCs, HydraSleeve®, the syringe ...
 
...should be discussed with the HEER Office before use. 6.5.7 Order of Groundwater Sampling Collect samples in groundwater monitoring wells no sooner than 14 days after ...
 
...Sampling Collect samples in groundwater monitoring wells no sooner than 14 days after well development. This delay applies to newly ...
 

6.6 Filtration of Groundwater Samples
...Micron Filter This filter type is typically used in the field collecting a filtered groundwater sample. An arrow on the body of the filter indicates the water flow direction when ...
 
...the filter. [Source: Aqua Merik, 2008] 6.6 FILTRATION OF GROUNDWATER SAMPLES Some contaminants and water quality parameters are impacted by excessive turbidity ...
 
...is important to avoid introducing turbidity into the water samples since the HEER Office groundwater EALs are intended for comparison to dissolved phase contaminants (and not contaminants adsorbed ...
 
... for sites near or adjoining the shoreline or in caprock substrate) filtering of groundwater samples prior to analysis for metals is generally accepted, and filtering for organic contaminants ...
 
... of the dissolved metal is dependent on the oxidation-reduction potential of the groundwater. In-situ groundwater is often under-saturated relative to the oxygen concentration in air. ...
 
...In-situ groundwater is often under-saturated relative to the oxygen concentration in air. Therefore, oxygen can ...
 
...relative to the oxygen concentration in air. Therefore, oxygen can dissolve from air into groundwater, resulting in an increased oxidation-reduction potential, which may change the oxidation ...
 
...metals and result in metal precipitation. It is therefore important to avoid aeration of groundwater collected for metals analysis. Aeration may occur during collection or transport. To ...
 
... results in a pH lower than 2, which keeps the dissolved metals in solution. A groundwater sample that is not filtered prior to preservation may yield false, elevated levels of dissolved-phase ...
 
...the laboratory. Due to the potential phase changes of metals that may occur during groundwater sampling and filtration, the HEER Office may require that analytical data for filtered samples ...
 
...filtered samples be accompanied by data for unfiltered samples, especially at sites where groundwater is used as a water supply or may discharge into a nearby surface water body. ...
 
...150 to 200 milliliters of sample to allow the filter to chemically equilibrate with the groundwater. Preserve the sample immediately upon filtration using proper preservation methods, in the ...
 

6.7 Aquifer Data Collection Methods
...determination of key characteristics used for evaluation of contaminant transport through groundwater. Hydraulic conductivity is a measure of the formation's ability to transmit water. It is therefore ...
 
... a certain change in hydraulic head. Hydraulic head is most commonly represented by groundwater elevation. Permeability of soil/rock samples can be determined in the laboratory and ...
 
...conductivity are slug tests and pumping tests. Both tests require access to one or more groundwater monitoring well(s) on site. Ensure that the wells are properly developed and in equilibrium ...
 
...commencing aquifer tests. On sites that are tidally influenced or show temporal groundwater fluctuations, monitor groundwater fluctuations in background wells throughout the duration ...
 
...fluctuations, monitor groundwater fluctuations in background wells throughout the duration of the aquifer test. The background ...
 
...may also be required at sites with stratified aquifers or those sites where vertical groundwater movement is significant. The guidance presented below is adequate for porous formations. ...
 
... hydraulic conductivity in fractured rock requires a different approach, since the groundwater flow may be turbulent. The slug test assumes that the aquifer is confined. For pumping ...
 
...of known volume (referred to as a "slug") from a well and continuously monitoring the groundwater level while the well recovers to its original level (Freeze et. al., 1979). Addition or ...
 
...The change in hydraulic head is monitored, usually in terms of drawdown, or change in groundwater elevation in the aquifer in response to pumping and removal of water from the formation. The ...
 
...is withdrawn from confined aquifers, the aquifer does not undergo dewatering, unless the groundwater elevation/head is lowered below the confining layer. The water is released from storage through ...
 

6.8 Groundwater Modeling
... ' 6.8 GROUNDWATER MODELING The purpose of groundwater modeling is to generate a visual representation of ...
 
...MODELING The purpose of groundwater modeling is to generate a visual representation of an aquifer including the overall groundwater ...
 
...modeling is to generate a visual representation of an aquifer including the overall groundwater movement, and in the case of contaminated sites, the fate and transport of contaminants. Groundwater ...
 
...movement, and in the case of contaminated sites, the fate and transport of contaminants. Groundwater modeling is also used to predict contaminant plume movement into the future or to predict the ...
 
...or to predict the aquifer and plume response to remedial activities. Groundwater modeling may be done manually by using a calculator or spreadsheet and then creating a graphical ...
 
...spreadsheet and then creating a graphical depiction of the data using flow nets. Manual groundwater modeling methods may be useful for creating preliminary site conceptual models intended ...
 
...and the initial contaminant plume extent. However, if the purpose of groundwater modeling is to predict how a contaminant plume changes over time or how it will respond to ...
 
...tool in the design of sampling strategies during site monitoring and in the design of groundwater remediation systems. Computer groundwater models are based on the geologic and hydrologic field ...
 
...remediation systems. Computer groundwater models are based on the geologic and hydrologic field data collected during drilling, geotechnical ...
 
... 6.8.1 Gradient and Flow Direction Determination The simplest way to determine the groundwater gradient and flow direction is by graphically constructing a flow net for the site. A flow ...
 
...lines connect points of equal head and the flow lines depict the interpreted groundwater flow path or flow direction. To construct a flow net for a site, measure the ...
 
...a flow net for a site, measure the hydraulic head in wells across the site following the groundwater gauging procedures detailed previously in this section. Enter the measurements onto a site ...
 
...above mean sea level or other datum plane. Add flow lines to depict the movement of groundwater at the site. Groundwater follows the path of steepest groundwater gradient. At a site where ...
 
...at the site. Groundwater follows the path of steepest groundwater gradient. At a site where the aquifer formation ...
 
...follows the path of steepest groundwater gradient. At a site where the aquifer formation is isotropic and porous, the steepest groundwater ...
 
...gradient. At a site where the aquifer formation is isotropic and porous, the steepest groundwater gradient is the shortest path between equipotential lines. The shortest path is perpendicular ...
 
...lines such that the flow is equally divided between adjacent lines. Calculate the groundwater gradient as follows: Measure the distance between two equipotential lines along a flow line, ...
 
... loss between the equipotential lines. Divide the head loss by the distance. The groundwater flow direction is along the flow lines. Depict flow lines as arrows pointing in the direction ...
 
...is along the flow lines. Depict flow lines as arrows pointing in the direction of groundwater flow, i.e., in the direction of declining hydraulic head. 6.8.2 Velocity, ...
 
...listed in Subsection 6.7, Aquifer Data Collection Methods. Calculate the groundwater velocity (v) using the following equation: v = q/ne = (K dh/dl) / ne ...
 
... v = q/ne = (K dh/dl) / ne Where: v = actual groundwater velocity q = Darcy velocity ne = effective porosity (connected ...
 
...Darcy velocity ne = effective porosity (connected pore space through which groundwater can flow) K = Hydraulic conductivity dh/dl = groundwater ...
 
...can flow) K = Hydraulic conductivity dh/dl = groundwater gradient (change in groundwater elevation in two wells over distance between the wells) ...
 
...gradient (change in groundwater elevation in two wells over distance between the wells) Compare the ...
 
...wells over distance between the wells) Compare the calculated groundwater velocity to the velocity range expected based on aquifer lithology. Note that ...
 
...has many consequences. For example, in a hydraulically isotropic, porous formation, the groundwater flow direction is perpendicular to the equipotential lines of the water table/potentiometric ...
 
...may be used at a site for many different goals including: (1) estimating how the actual groundwater system functions; (2) selecting sampling approaches, objectives and locations; (3) predicting ...
 
...are relatively more simplistic, offer an inexpensive method to conduct preliminary groundwater analysis, and may be useful during the early phases of a project. Numerical approaches are ...
 
...knowledge and software. However, numerical approaches easily deal with variability in the groundwater flow and contaminant transport parameters, which provides flexibility in representing complex ...
 
...remedial solutions and for the evaluation of environmental hazards. A groundwater modeling report should, at a minimum, include (USEPA, 1992a): Previous studies ...
 

6.9 Surface Water Sample Collection Methods
...Filtration For surface water filtration follow the same procedures outlined for groundwater filtration of groundwater samples (Subsection 6.6, Filtration). ...
 
... filtration of groundwater samples (Subsection 6.6, Filtration). ...
 

7.0 Soil Vapor and Indoor Air Sampling Guidance
...risks posed to outdoor air and overlying buildings. The development of HDOH soil, groundwater and soil gas (�vapors�) action levels for evaluation of vapor intrusion hazards is described ...
 
...the document Evaluation of Environmental Hazards at Sites with Contaminated Soil and Groundwater (�EHE guidance;� HDOH 2011, see also PBEHE 2012). The discussion provided below and ...
 

7.1 Soil Vapor Transport Mechanisms and Conceptual Models
...storage tanks. The emission of volatile chemicals from contaminated soil and groundwater can create a plume of vapors in the vadose zone. These plumes can adversely impact indoor air ...
 
...(see HDOH 2011). Vapors in vadose-zone soil could also migrate downwards and impact groundwater that has otherwise not been directly affected by the release. This has been recognized, for ...
 
...associated with the presence of relatively shallow, free product in vadose-zone soil or groundwater (see USEPA 2013). Under most site scenarios, the breakdown of petroleum compounds ...
 
...lead to potential vapor intrusion concerns even in the absence of free product in soil or groundwater. Dilute plumes of solvent-contaminated groundwater have, for example, been documented to travel ...
 
...Dilute plumes of solvent-contaminated groundwater have, for example, been documented to travel thousands of feet downgradient of initial release ...
 
...during an earlier period of operation. The presence of high levels of vinyl chloride in groundwater or soil vapor at sites often indicates the presence of co-located petroleum contamination. ...
 
...presence of petroleum. The presence of significant breakdown products in soil vapor or groundwater signifies the need to look for petroleum contamination in the same area. ...
 

7.2 Soil Vapor Intrusion to Indoor Air
...soil of equal magnitude, especially in the case of petroleum releases that have reached groundwater. As the water table falls and exposes this smear zone, an increase in vapor emissions can occur. ...
 
...on the expected subsurface geology, depth to the potential source contaminants or groundwater, and actual or potential human or environmental receptors, as well as other specific information ...
 
...transport includes the outward diffusion of vapor-phase chemicals from impacted soil or groundwater and the potential advective flow of the vapors into an overlying building (Figure 7 1). ...
 
...observed with petroleum hydrocarbon or volatile organic compounds (VOC) impacted soil and groundwater (Figure 7-2). The biodegradation processes include aerobic and anaerobic degradation of contaminants ...
 

7.3 Characterization, Delineation and Monitoring
...action levels for rapid screening of suspect sites. Development of the HDOH soil, groundwater and soil gas (�vapor�) action levels for vapor intrusion is discussed in the HDOH EHE guidance ...
 

7.4 Soil Vapor Probe Installation
...air samples are collected following the discovery or identification of subsurface soil or groundwater contamination containing volatile or semi-volatile constituents. In addition to the evaluation ...
 
...be carried out in a manner that minimizes stripping of VOCs from free product in soil or groundwater or stripping of VOCs otherwise sorbed to soil particles or dissolved in groundwater and not ...
 
...or stripping of VOCs otherwise sorbed to soil particles or dissolved in groundwater and not initially present in the vapor phase. This is accomplished primarily by minimizing ...
 
...additional stripping of VOCs in product, sorbed to soil particles or dissolved in groundwater. HDOH is currently studying approaches for the collection of representative and ...
 

7.6 Soil Vapor Sample Collection Procedures
...samples are collected to help locate and characterize areas of contaminated soil and groundwater that might require remediation or long-term management. The direct collection of groundwater ...
 
...that might require remediation or long-term management. The direct collection of groundwater samples is generally adequate to identify contamination with volatile chemicals. This is because ...
 
...contamination tends to become dispersed over relatively large areas due to diffusion and groundwater flow. The additional collection of soil vapor samples to assist in the identification ...
 
...collection of soil vapor samples to assist in the identification of areas of contaminated groundwater is typically not necessary or required. Note, however, that groundwater action ...
 
...is typically not necessary or required. Note, however, that groundwater action levels presented in the HDOH EHE guidance are not applicable for sites where the depth ...
 
...levels presented in the HDOH EHE guidance are not applicable for sites where the depth to groundwater is less than ten feet due to limitations in the models and data used to develop the levels. ...
 
...also be considered. Direct collection of soil vapor samples regardless of soil and/or groundwater data is also recommended for sites with a very high potential for the release of volatile chemicals. ...
 
...stations and dry cleaners (see Section 7.6.2.2). As is the case for groundwater, volatile chemicals in subsurface soils tend to more evenly disperse over relatively large ...
 
...approach for the initial evaluation of vapor intrusion hazards at sites where soil or groundwater is contaminated with volatile chemicals (HDOH 2011): ...
 
... Contaminants in Vadose Zone 2Soil and/or 3Groundwater Pose Potential Vapor Intrusion Hazards ...
 
...suspected (e.g., PCE vapors under a dry cleaner). Free product on groundwater table or dissolved VOC concentrations above Tier 1 groundwater action levels for vapor ...
 
...table or dissolved VOC concentrations above Tier 1 groundwater action levels for vapor intrusion. VOC concentrations ...
 
...intrusion. VOC concentrations below Tier 1 EALs for both soil or groundwater and significant volume (e.g., >10m3) of VOC-contaminated soil or other potential ...
 
... vapors under a building slab not suspected. Compare groundwater and soil analytical data to appropriate HDOH environmental action levels (EALs) ...
 
...in Evaluation of Environmental Hazards at Sites with Contaminated Soil and Groundwater (HDOH 2011) or site-specific action levels approved by HDOH. See Table C-1a for Groundwater ...
 
...(HDOH 2011) or site-specific action levels approved by HDOH. See Table C-1a for Groundwater Action Levels and Table C-1b for Soil Action Levels, located in Appendix 1 of the EHE document; ...
 
...results to Shallow Soil Gas Action Levels for areas over or near a plume where Groundwater and/or Soil EALs for vapor intrusion are approached or exceeded or sites where a potentially ...
 
...vapor sampling is recommended (Step 2) based on the occurrence of VOCs in soil and/or groundwater and the distance between the building and the source area. The initial ...
 
...soil; see Appendix 1 in HEER EHE guidance, HDOH 2011). Thin lenses of perched groundwater can further reduce upward vapor flux. Aerobic biodegradation of non-chlorinated, vapor-phase, ...
 
...within a few feet of a source area (e.g., heavily contaminated soil or free product on groundwater). A discussion of targeted chemicals of concern for petroleum releases is provided ...
 
...mass or concentration of petroleum in underlying soil or the presence of free product on groundwater (e.g., Abreu et. al 2009, McHugh 2010; USEPA 2013). For dissolved-phase contaminants a �vertical ...
 
... is at a depth of greater than fifteen feet year round and no free product is present on groundwater and contaminated soil is not present in the vadose zone, then potential vapor intrusion hazards ...
 
...intrusion hazards are unlikely to be posed by dissolved-phase petroleum contaminants in groundwater under any site scenario due to low source strength and rapid biodegradation of vapors ...
 
...Large volumes of shallow, contaminated soil or widespread free product on shallow groundwater (i.e., <30ft deep) could lead to the accumulation of vapors under caps and a progressive ...
 
...overlie deep (i.e., >30ft) widespread, heavily contaminated soil or free product on groundwater. Such scenarios could be possible with large releases from fuel pipelines, fuel hydrant ...
 
...provided in the HEER guidance Long-Term Management of Petroleum-Contaminated Soil and Groundwater HDOH 2007c). 7.6.2 Soil Vapor Sampling Design ...
 
...vapor sampling strategy depends on site-specific conditions, including soil types and groundwater levels, the number and size of existing buildings, and current site use or future development ...
 
...of the source area because soil vapor can migrate in a different direction than groundwater flow. When assessing upward, vertical migration, vapor samples from multiple depths may be ...
 
... Figure 7-4: Schematic of Soil Vapor Concentration Profile. VOCs volatilize out of a groundwater plume and diffuse vertically toward the surface. Vapor phase concentrations are highest ...
 
...diffuse vertically toward the surface. Vapor phase concentrations are highest at the groundwater-vadose zone interface and decrease with decreasing depth. Vapors can accumulate under buildings ...
 
...likely might not mimic the shape of the primary source area (i.e., contaminated soil or groundwater). This is because the outward, lateral migration of vapors away from the source area is strongly ...
 
...a depth of five to ten feet below ground surface (or no more than two to three feet above groundwater for shallow water tables) in order to take into consideration the potential buildup of vapors ...
 
...periods of time in the vadose zone following active, in situ remediation of contaminated groundwater (�residual vapor plume,� see Table 7-1). The San Diego County Site Assessment and ...
 
...as the nature and magnitude of the release, the subsurface geology and the depth to groundwater. The investigation of potential vapor intrusion hazards will require the placement of sample ...
 
...of ten feet for petroleum-contaminated sites or no more than two to three feet above groundwater for sites with a shallow water table. This is necessary in order to take into consideration ...
 
...site conditions. Note that the same is true with respect to the representativeness of a groundwater sample collected from a five-foot, monitoring well screen or from a much smaller interval ...
 

7.7 Indoor Air Sample Collection Procedures
...potential vapors is present below the building (e.g., petroleum free product on shallow groundwater) then the collection of source area soil vapor samples is also recommended (see ...
 

7.8 Soil Vapor or Indoor Air Sample Analysis
...of soil vapor or indoor air samples can be more involved and complex than soil or groundwater sample collection. This is due in part to the need for special sampling equipment and containers ...
 
...of these approaches is provided in Table 7-3. Similar to soil and groundwater sample collection, a combination of sampling approaches can be used if analyzing for a broad ...
 
...environment (e.g., to evaluate TPH in vapors associated with diesel-contaminated soil or groundwater) and the volume of vapors to be drawn is less than one liter then the concurrent collection ...
 
...to the PDS sample after collection should be considered in the similar manner as done for groundwater samples (see Section 6). The water is then analyzed for targeted VOCs, with results ...
 

7.9 Gas Phase Sample Evaluation
... 7.9.2 Permanent Probes Permanent probes are constructed similar to groundwater monitoring wells installed using auger or direct push drilling techniques. However, permanent ...
 

7.10 Documentation of Soil Vapor or Indoor Air Sampling
...seasonal weather variations and associated water table fluctuations and tidal effects on groundwater elevation. Multiple sampling events are recommended if the conceptual model identifies the ...
 
...vapor concentrations at high-risk, coastal sites with significant free product on shallow groundwater. At sites near the coast, the tides can affect groundwater levels, soil vapor samples ...
 
... At sites near the coast, the tides can affect groundwater levels, soil vapor samples should be collected at the same point in the tidal cycle in order ...
 
...A minimum of one round of samples should be collected at chlorinated solvent sites where groundwater action levels are approached or exceeded or a significant source is present in the ...
 
...1) Sites with widespread, heavy contamination in vadose-zone soil and/or floating on groundwater within 30 vertical feet or 100 lateral feet of a building slab that do not meet the above-noted ...
 

7.0 Soil Vapor and Indoor Air Sampling Guidance
...document Screening for Environmental Hazards at Sites with Contaminated Soil and Groundwater (Environmental Hazard Evaluation [EHE] guidance [HDOH 2011]). In the EHE guidance, ...
 

9.1 Pesticide Contamination at Former Agricultural Facilities and Sites
...contamination could also pose leaching hazards and subsequent contamination of underlying groundwater resources (e.g., triazine pesticides and fumigants). This generally requires that the full ...
 
...from four to fourteen inches below ground surface. DBCP and EDB have been detected in groundwater wells on Oahu and Maui and have not been used since the mid-1980s (HDOH 1985, ...
 
...(TCP) is an impurity associated with D-D and has also been detected in groundwater wells in the state (see HDOH 1985) Fumigants are not likely to be ...
 
...direct-exposure concern, these chemicals can still pose leaching threats to underlying groundwater. Comparison to screening levels that do not consider leaching is therefore not appropriate ...
 

9.3 Petroleum Contaminated Sites
...category of Total Petroleum Hydrocarbons (TPH). The concentration of TPH in soil and groundwater is typically reported in terms of "carbon ranges," or the number of carbon molecules in individual ...
 
...aliphatics (HDOH 2011, 2012). Although not studied in detail, dissolved-phase gasoline in groundwater is also likely to be biased towards more soluble, lighter-range compounds. ...
 
... releases of middle distillate fuels. Dissolved-phase, middle-distillate fuel in groundwater could also be biased towards more soluble, "gasoline-range" compounds. A dominance of "TPHg" ...
 
...also be biased towards more soluble, "gasoline-range" compounds. A dominance of "TPHg" in groundwater samples does not in itself indicate that the source of the contamination is associated with ...
 
...not practicable. This guidance, Long-Term Management of Petroleum-Contaminated Soils and Groundwater (HDOH, 2007c) is included in TGM Section 19 as Appendix 19-A. The document includes ...
 
...database is possible in scenarios where the area and volume of contaminated soil and/or groundwater is minimal. Table 9-5 Target Analytes for Releases of Petroleum Products ...
 
...and methane Groundwater Same as soil ...
 
...and methane Groundwater Same as soil ...
 
...and methane Groundwater same as soil ...
 
...Analytes Recommended target analytes for petroleum contaminated soil and groundwater are provided in Table 9-5. Petroleum contamination in soil, water or air/soil ...
 
...waste. 9.3.1.2 Total Petroleum Hydrocarbons Soil, groundwater, and soil vapor samples must always be tested for TPH (or equivalent) in addition to targeted, ...
 
...warranted. Silica gel cleanup of samples, in particular for surface water and groundwater, should not be carried out without consultation with HDOH. Two options are recommended: ...
 
...for the sample. The polar compounds, which can dominate the overall mass of TPH in groundwater at aged-release sites, are primarily organic acids/esters and alcohols with variable amounts ...
 
...for comparison to data. In most cases, it is anticipated that long-term management of groundwater contaminated primarily with polar, TPH breakdown compounds above HDOH action levels will still ...
 
...(e.g., via impacts to drinking water resources). Comparison of data for groundwater samples tested with and without silica gel cleanup could be useful for assessing the state ...
 
...assessing the state of natural biodegradation within a plume of petroleum-contaminated groundwater and optimizing remedial and monitoring actions. For example, no further active remediation ...
 

10.3 Data Quality Assurance Procedures
...replicates (triplicates for MIS). Groundwater duplicates 1 per day for every 10 samples ...
 
...as a Relative Standard Deviation (RSD) percent: Groundwater field duplicates are evaluated by determining a RPD for the replicates, using RPD formula as ...
 
...In some cases, additional care must be taken to evaluate comparability. For instance, groundwater samples handled in the exact same fashion, collected within the same sampling event, ...
 

10.6 Field QA/QC
...or triplicate samples collected from within the same decision unit or from the same groundwater well to evaluate the precision of the sampling effort. Replicates are to be collected, preserved, ...
 
... 10.6.1.1 Discrete Sampling Replicates In general, for discrete sampling of groundwater or soil the HEER Office recommends collecting one replicate QA/QC sample per field day per ...
 
...and co-located sample data compared to ensure these DQO are met. Duplicate groundwater samples For non-volatile groundwater contaminants collected in vials, generally two sample ...
 
...samples For non-volatile groundwater contaminants collected in vials, generally two sample containers are "alternately" filled. ...
 
...would be filled by going back and forth with the discharge tubing. For volatile groundwater contaminants, where multiple 40 ml vials are commonly used for each sample and loss of volatiles ...
 

Contents
... Laboratory Methods, Containers, Preservation, and Holding Times for Groundwater Samples   ...
 

11.0 Handling and Analysis of Samples
...analytical methods for each sampling event. This section focuses on soil and groundwater samples collected as part of an environmental investigation, which are sent to a fixed laboratory ...
 
...is presented on the use of soil sampling equipment in Section 5 and on the use of groundwater or surface water sampling equipment in Section 6. A discussion of gas phase samples is not ...
 

Appendices
... Laboratory Methods, Containers, Preservation, and Holding Times for Groundwater Samples ...
 

11.1 Sample Containers
... Table 11-B in the Appendix 11-B present the recommended sample containers for groundwater. The sample volumes for the containers listed in the tables represent the recommended size ...
 
...one sample container may be required for the associated parameter and method. If soil or groundwater samples are to be analyzed for multiple contaminants, the sample volumes listed in the tables ...
 
...Sample Containers The type of sample container used for collecting surface water or groundwater samples is dependent upon the specific analysis to be performed. Other factors, such as ...
 
...in 1 liter amber glass jars without the use of chemical preservatives. When collecting groundwater samples, fill the water sample containers by directing the outlet of the sampling ...
 
...should be carefully placed on the jars and sealed with zero headspace. When collecting groundwater samples for volatile analysis, fill the 40 mL jars by directing the outlet of the sampling ...
 

11.2 Sample Preservation and Hold Times
...in the Appendices, present the recommended preservation and hold times for soil and groundwater, respectively. Sample preservation consists of methods to assure the samples analyzed ...
 
... chemical reagents from the analytical laboratory. Carefully place the soil or groundwater samples into the sample containers to minimize loss of chemical preservative as well ...
 
...the sample media. For example, calcareous soil may react with sodium bisulfate; turbid groundwater collected from a coral aquifer formation may react with hydrochloric acid. If the sample media ...
 
... Some samples collected for specific analysis, such as dissolved metals in groundwater, may require pre-treatment prior to collection, as well as preservation (see ...
 

11.3 Sample Control and Chain-of-Custody Procedures
...sample media in chain-of-custody batches for submittal to the laboratory (i.e., submit groundwater samples on one chain-of-custody batch separate from soil samples collected for the same project). ...
 

11.4 Sample Shipping
...samples (i.e., no chemical preservatives added during collection). For groundwater samples specifically, very small quantities of certain dangerous goods may be transported without ...
 

11.5 Approved Analytical Methods
... 11-B in the Appendices provide the recommended analytical methods for soil and groundwater analysis, respectively. Use other EPA-approved methods (such as Methods for Chemical ...
 

Appendix 11-B Tables
... Laboratory Methods, Containers, Preservation, and Holding Times for Groundwater Samples ...
 

Contents
... Summary of Action Levels Used to Select Tier 1 Soil and Groundwater EALs for Benzene   ...
 
...Hazard Identification Page, Using Benzene at Noted Concentration in Soil and Groundwater as an Example   ...
 
...EAL Surfer EHE Summary Report, Using Benzene at Noted Concentration in Soil and Groundwater as an Example   ...
 
... Environmental Hazard Map for Hypothetical Site with Groundwater Contamination   ...
 

13.0 Environmental Hazard Evaluation
...document Screening for Environmental Hazards at Sites with Contaminated Soil and Groundwater (HDOH, 2011). Environmental Hazard Evaluation (EHE) is the link between site investigation ...
 
...actions carried out to address hazards posed by the presence of contaminated soil and groundwater, as shown in Figure 13-1. Figure 13-1. Expanded Overview ...
 
...or absence of potential environmental hazards associated with contaminated soil and groundwater is determined and summarized in an EHE (i.e., a review of potential environmental hazards), ...
 
... absence of a basic understanding of environmental hazards posed by contaminated soil or groundwater run the risk of being incomplete, and require unanticipated, additional field work. This can ...
 
... entitled Screening for Environmental Hazards at Sites with Contaminated Soil and Groundwater (HDOH, 2011). Readers unfamiliar with the concept of environmental hazard evaluation may be ...
 

Figures
... Summary of Action Levels Used to Select Tier 1 Soil and Groundwater EALs for Benzene   ...
 
...Hazard Identification Page, Using Benzene at Noted Concentration in Soil and Groundwater as an Example   ...
 
...EAL Surfer EHE Summary Report, Using Benzene at Noted Concentration in Soil and Groundwater as an Example   ...
 
... Environmental Hazard Map for Hypothetical Site with Groundwater Contamination ...
 

13.1 Target Environmental Hazards
... Contaminated Groundwater ...
 
... Toxicity concerns related to contamination of groundwater that is a current or potential source of drinking water ...
 
... Emission of volatile contaminants from groundwater and intrusion into overlying buildings ...
 
... Discharges of contaminated groundwater and toxicity to aquatic organisms. Includes contamination of fish and shellfish ...
 
...water (rainfall, irrigation, etc.) and subsequent contamination of groundwater resources ...
 
... Emission of volatile contaminants from soil or groundwater into overlying buildings and/or outdoor air. ...
 
...Levels. The four target media tested to evaluate these potential hazards are groundwater, soil, soil gas and indoor air. A summary ...
 
...or subsurface utility activities that require disturbance of heavily contaminated soil or groundwater. Leaching of contaminants from soil is also important to consider, even though this ...
 
...this is rarely included in traditional risk assessments. Discharges of contaminated groundwater or free product into nearby surface water bodies, either naturally or via leakage ...
 
...pose significant environmental hazards to aquatic habitats. When large plumes of impacted groundwater threaten fisheries, the discharge of contaminated groundwater to surface water and subsequent ...
 
...threaten fisheries, the discharge of contaminated groundwater to surface water and subsequent uptake of contaminants into seafood may also be of concern. ...
 
...aquifers. Potential vapor intrusion hazards will also usually be identified for groundwater contaminated with carcinogenic, volatile chemicals. Chemicals that have a low taste ...
 
... drinking water standards. This can drive remedial actions if discharge of contaminated groundwater into a sensitive aquatic habitat is possible. Free product could pose both toxicity and gross ...
 
...attention at some sites, including exposure of construction workers to contaminated groundwater and the potential uptake of contaminants in garden produce. The need to include additional ...
 

13.2 Tier 1 Environmental Action Levels
...Evaluation guidance (HDOH, 2011). This guidance presents soil gas as well as soil and groundwater action levels for screening of potential vapor intrusion hazards. The action levels are periodically ...
 
...also provided. This is used in part to caution against use of the HDOH soil gas, soil and groundwater action levels for vapor intrusion in colder areas of the US where heating and overall building ...
 
...default, Indoor Air:Subslab Soil Gas attenuation factors used to develop the HDOH soil, groundwater, soil gas ("vapor") and indoor air action levels for potential vapor intrusion hazards are ...
 
... soil gas action levels (see HDOH, 2011). Note that the USEPA vapor intrusion model for groundwater calculates a vapor flux rate of 67.4 cm3/second or 4.0 L/minute, based on input, default building ...
 
...(see HDOH, 2011, Appendix 4). This generates an AF of 0.0010 (1/1,017) as used the groundwater vapor intrusion models. The AFs used between the soil gas and groundwater models are therefore ...
 
...vapor intrusion models. The AFs used between the soil gas and groundwater models are therefore consistent. The residential AF was divided by two (0.0005) for development ...
 
...see Section 7.7.1). Virtually any detection of volatile chemicals in soil, groundwater, soil vapors, or indoor air would trigger a time and cost consuming assessment of ...
 

13.3 Steps to Environmental Hazard Evaluation
...Action Levels (Tier 1 EALs) are concentrations of contaminants in soil, soil gas and groundwater below which the contaminants are assumed to not pose a significant threat to human health or ...
 
...document Screening for Environmental Hazards at Sites with Contaminated Soil and Groundwater (HDOH, 2011). The EALs described in the EHE document are not intended to establish policy or ...
 
...representation of site environmental conditions with respect to contaminated soil and groundwater and related environmental hazards (see Section 3.4.3). Four default CSMs were used ...
 
...Four default CSMs were used to develop The Tier 1 EALs (HDOH, 2011): Groundwater affected or potentially affected by the release is a current or potential drinking water ...
 
...drinking water resource; site located within 150m of a surface water body. Groundwater affected or potentially affected by the release is a current or potential drinking water ...
 
...water resource; site not located within 150m of a surface water body. Groundwater affected or potentially affected by the release is not a current or potential drinking ...
 
...drinking water resource; site located within 150m of a surface water body. Groundwater affected or potentially affected by the release is not a current or potential drinking ...
 
...water body. Only surface water bodies that are hydraulically connected to groundwater are considered to be potentially threatened by contaminated groundwater. For the purposes of ...
 
...are considered to be potentially threatened by contaminated groundwater. For the purposes of the Tier 1 EALs, it is further assumed under each default CSM that contaminated ...
 
...HDOH document Evaluation of Environmental Hazards at Sites with Contaminated Soil and Groundwater for additional information on site conditions assumed for development of the Tier 1 EALs (HDOH, ...
 
...as the Tier 1 EAL [refer to lookup tables in HDOH EAL document (HDOH, 2011)]. For groundwater, the action level for drinking water toxicity concerns drives environmental hazards and is ...
 
... Figure 13-4. Summary of Action Levels Used to Select Tier 1 Soil and Groundwater EALs for Benzene. CSM A based on (1) groundwater is a drinking water resource, and ...
 
... EALs for Benzene. CSM A based on (1) groundwater is a drinking water resource, and (2) site within 150m of a surface water body. For ...
 
...water resource, and (2) site within 150m of a surface water body. For soil and groundwater, the lowest action level for environmental hazards is selected as the final Tier 1 ...
 
...Surfer, simply select the appropriate site scenario information from the pull-down list (groundwater utility, distance to nearest surface water body, land use, etc.), select the target contaminant, ...
 
...and (optional) input the representative concentration of the contaminant in soil and/or groundwater. If included, the input concentration is compared to action levels for specific environmental ...
 
... levels for leaching hazards are unchanged because land use does not alter the threat to groundwater. Groundwater action levels for vapor intrusion hazards are also higher for a commercial/industrial ...
 
...Groundwater action levels for vapor intrusion hazards are also higher for a commercial/industrial land ...
 
...soil is located within three meters of the ground surface ("shallow") and overlies groundwater that is a current or potential source of drinking water. The site is within 150 meters ...
 
...are not flagged as potential hazards. The input concentration of 150 ug/L benzene in groundwater flags drinking water toxicity concerns and aquatic ecotoxicity concerns, but no other potential ...
 
...Data used for this example was 5.1 mg/kg benzene in soil, and 150ug/L benzene in groundwater. Also, check for updates. The EAL Surfer is updated periodically and the page configurations ...
 
...Hazard Identification Page, Using Benzene at Noted Concentration in Soil and Groundwater as an Example. Refer also to Figure13-5a. ...
 
...EAL Surfer EHE Summary Report, Using Benzene at Noted Concentration in Soil and Groundwater as an Example. Refer also to Figure13-5a. This page can be printed and included in ...
 
...is to determine the extent of investigation needed at a site where contaminated soil or groundwater is identified. The list of Chemicals of Potential Concern (COPCs) can be quickly narrowed down ...
 
...Potential Concern (COPCs) can be quickly narrowed down by direct comparison of soil and groundwater data to the Tier 1 EALs (HDOH, 2011). Further consideration of contaminants that do not exceed ...
 
...3 and Section 9 ). If the reported concentration of volatile contaminants in soil or groundwater exceed action levels for vapor intrusion concerns, then soil gas data can be collected ...
 
...identification of potential environmental hazards associated with contaminated soil and groundwater (refer to Section 3.4). With the exception of gross contamination, most of the environmental ...
 
...gas action levels in this guidance helps expedite this evaluation. A detailed review of groundwater data can sometimes be used in place of soil action levels to better evaluate leaching and groundwater ...
 
...data can sometimes be used in place of soil action levels to better evaluate leaching and groundwater contamination concerns. In other cases, additional laboratory tests and/or use of environmental ...
 
...action levels to understand the specific environmental hazards posed by contaminated groundwater is especially important. Identifying toxicity hazards and taste and odor hazards in groundwater ...
 
...is especially important. Identifying toxicity hazards and taste and odor hazards in groundwater that is currently used as a source of drinking water is obviously important. Expeditious actions ...
 
...soil are usually warranted. In contrast, long-term monitoring may be acceptable for groundwater that poses only gross contamination hazards (e.g., toxicity-based action levels for currently ...
 
...of surface water. Long-term management will be required for sites where soil and groundwater contaminated above levels of potential concern cannot be remediated in a relatively short time ...
 
... acceptable alternatives) should be used to delineate areas of contaminated soil and groundwater that will require long-term management as well as the specific environmental hazards posed ...
 
...below commercial laboratory Method Reporting Limits (MRLs) for a number of chemicals in groundwater. This is not generally the case for soil. As discussed in the EHE guidance, the laboratory ...
 
...2011). Chemicals with laboratory MRLs that could exceed the HDOH EALs for groundwater are given in Table 13-2. If the reported concentration of a chemical exceeds ...
 
... Groundwater Soil ...
 

13.4 Preparation of Environmental Hazard Evaluation Reports
... ' 13.4 CHEMICALS NOT LISTED IN LOOKUP TABLES Soil, groundwater, soil gas and/or indoor air action levels should be developed and approved by HDOH for chemicals ...
 

13.5 Human Health Risk Assessments
...to begin to identify potential environmental hazards at a site as soon as initial soil, groundwater and other data are received. As discussed above, this is used to guide completion of the site ...
 
...to the HDOH Screening for Environmental Hazards at Sites with Contaminated Soil and Groundwater guidance document (HDOH, 2011). The list of COPCs can be quickly narrowed down ...
 
...(DU) and the representative concentration of target COPCs within each DU determined. For groundwater and soil gas samples, direct reference to reported concentrations of COPCs in single ...
 
...document Screening for Environmental Hazards at Sites with Contaminated Soil and Groundwater ["EHE guidance" (HDOH, 2011)]. A summary of commonly used approaches is provided in Tables ...
 
...a much lower vapor intrusion hazard than predicted by simple comparison of soil or groundwater data to HEER Office action levels. The additional data could negate the need for remedial actions ...
 
...can help identify the presence of contamination that was not detected in earlier soil and groundwater sample collection. Preparing a traditional human health risk assessment or ecological ...
 
...focuses on toxicological risks associated with direct exposure to contaminated soil, groundwater, or air. While this is important, direct exposure is only one of several potential environmental ...
 
... Table 13-3 Commonly Used Approaches for Evaluating Environmental Hazards in Groundwater ...
 
... �    Identification and monitoring of nearby, groundwater supply wells and guard wells ...
 
... �    Long-term monitoring of groundwater to evaluate plume migration potential ...
 
... potential �    Use of groundwater plume fate & transport models in combination with long-term monitoring ...
 
... �    Use of groundwater data to evaluate plume expansion and migration over time ...
 
...fate and transport models to predict long-term migration potential of groundwater contaminant plumes �    Preparation ...
 
... �    Check groundwater for free product �    Check discharge ...
 
... �    Collection of groundwater data �    Use of HDOH laboratory ...
 
...spill area, not the site as a whole, is the target where the "receptor" of concern is the groundwater directly underneath the contaminated soil. If Tier 1 soil action levels for leaching ...
 
...carried out. Keep in mind that soil data are not necessarily good indicators of potential groundwater contamination. This is especially true for chlorinated solvents. Releases of wastewater contaminated ...
 
...of the solvent compounds, even though the release results in significant contamination of groundwater. Soil or groundwater data flagged for potential vapor intrusion almost always indicates ...
 
... Soil or groundwater data flagged for potential vapor intrusion almost always indicates that soil gas samples should ...
 
...soil gas samples should be collected at the site. The model used to develop the soil and groundwater actions levels for vapor intrusion hazards estimates the concentration of a volatile contaminant ...
 
...buildings located in this area. Documenting where grossly contaminated soil and groundwater will be left in place at a site is also important (e.g., Figure 13-7). Gross contamination ...
 
...13-7). Gross contamination hazards often drive the cleanup of contaminated soil and groundwater, not direct exposure or even leaching hazards. Over time, grossly contaminated soil and groundwater ...
 
...not direct exposure or even leaching hazards. Over time, grossly contaminated soil and groundwater can generate methane and related explosive hazards. Although the contamination may not pose ...
 
...under current site conditions, the unexpected discovery of grossly contaminated soil and groundwater during subsurface construction or utility activities can result in significant delays and project ...
 
... Figure 13-7. Environmental Hazard Map for Hypothetical Site with Groundwater Contamination. Hypothetical site contaminated with petroleum. Areas delineated by ...
 
...vapor intrusion hazard so property can be redeveloped. Aggressive remediation of groundwater that poses acute aquatic toxicity hazards and gross contamination (odors, sheens) within ...
 
...50 meters of the shoreline is also recommended. Long-term monitoring of remaining groundwater contamination required (see text). ...
 
...of contaminants over time, etc. When practicable, full cleanup of contaminated soil and groundwater to permit future, unrestricted use of the property is desirable. A detailed discussion ...
 
...capping of contaminated soil to prevent exposure or leaching, long-term monitoring of groundwater, etc. These actions must be described in a site-specific EHMP. The preparation of ...
 

13.6 Ecological Risk assessements
...HDOH document Screening for Environmental Hazards at Site with Contaminated Soil and Groundwater (HDOH, 2011). A summary of the type of information that should be included in the report is ...
 
... Identify all types of impacted media (soil, groundwater, surface water, etc.). Identify all sources of chemical releases. ...
 
...applicable (include maps of site with isoconcentration contours for soil and groundwater as practicable). Identify nearby groundwater extraction wells, ...
 
...as practicable). Identify nearby groundwater extraction wells, bodies of surface water and other potentially sensitive ecological ...
 
... addition to an Environmental Hazard Evaluation)? Do soil and groundwater conditions at the site differ significantly from those assumed in development of ...
 
...health effects been identified? Selection of soil and groundwater categories: State the regulatory beneficial use ...
 
... State the regulatory beneficial use of impacted or potentially impacted groundwater beneath the site; discuss the actual, likely beneficial use of groundwater based ...
 
...beneath the site; discuss the actual, likely beneficial use of groundwater based on measured or assumed quality of the groundwater and the hydrogeologic nature ...
 
...based on measured or assumed quality of the groundwater and the hydrogeologic nature of the soil or bedrock containing the groundwater. Characterize ...
 
...and the hydrogeologic nature of the soil or bedrock containing the groundwater. Characterize the soil type(s) and location of impacted soil as ...
 
...site data to the selected summary Tier 1 EALs and identify areas of soil or groundwater that pose potential environmental hazards. Identification ...
 
... to assess the need for potential cleanup actions at sites where contaminated soil and groundwater are identified. ...
 

14.2 Removal Actions for Non-Emergency Environmental Cleanups
...2008] for soil and surface waters) Reducing possible future impacts to groundwater Restoring the pond to stable conditions where vegetation and animals may be re-established ...
 
...longer-term threats posed by residual contamination of subsurface soils and non-drinking groundwater also exist, these less imminent hazards may be left for a non-emergency removal or remedial ...
 

15.1 FTC Overview
... entitled the "Evaluation of Environmental Hazards at Sites with Contaminated Soil and Groundwater" (HDOH, 2008). 15.1.1 Difference from Other Approaches While ...
 

15.3 Screening And Eligibility
... Contamination that is known or likely to extend across a property boundary Groundwater contamination, especially in a drinking water aquifer Soil contamination that has a migration ...
 

15.5 Site Assessment Process
...characterize site conditions in order to identify the necessity for remediating soil or groundwater that poses unacceptable environmental hazards, either under current site conditions or under ...
 
... The site assessment is carried out by the collection and analyses of samples of soil, groundwater, soil gas, surface water, sediment, air and/or other media as needed. The EALs may be used ...
 
...presence or absence of potential hazards may be identified and the contaminated soil or groundwater quickly remediated without further assessment. In cases where cleanup costs could ...
 

15.6 Site Cleanup Process
... Cause of release or threat Site history General site geology, hydrology, groundwater status, adjacent land uses Distance to surface water bodies Site investigation and ...
 

Contents
... 16.2.2.4 Groundwater Remedial Actions   ...
 

16.0 Remedial Actions
...may decide on a remedial action approach under the following conditions: Groundwater contamination, especially in a drinking water aquifer Soil contamination with a direct migration ...
 
...with a direct migration pathway to a nearby drinking water aquifer Contamination (soil or groundwater) crosses property boundaries Contaminants are present at high levels or consist of complex ...
 

16.1 Conducting a Remedial Investigation
...sites, municipal landfills, volatile organic compounds (VOCs) in soils, and contaminated groundwater for Comprehensive Environmental Response, Compensation & Liability Act (CERCLA) ...
 

16.2 Setting Remedial Action Objectives and Conducting a Remedial Alternatives Analysis
...Refer to the EALs provided in Evaluation of Hazards at Sites with Contaminated Soil and Groundwater (HDOH, 2008). Known or suspected carcinogens: Cleanup levels should be concentrations ...
 
... to the EALs provided in Evaluation of Hazards at Sites with Contaminated Soil and Groundwater (HDOH, 2008). Ecological receptors: Where these concerns are identified, cleanup levels ...
 
... Soil vapor extraction to extract volatile contaminants from subsurface soils Groundwater extraction, filtration by activated carbon, and disposal of the carbon in an approved ...
 
...vapor barriers or active ventilation systems On-site containment of contaminated groundwater with sheet piles or slurry walls Reducing mobility of free phase petroleum in soil ...
 
...sheet piles or slurry walls Reducing mobility of free phase petroleum in soil or groundwater by removing petroleum to residual saturation or less ...
 
... left in place is disturbed in the future. Long-term monitoring of a "stable" groundwater contaminant plume Public notices and advisories against consumption of contaminated ...
 
..."free product" from the water table to prevent continued contamination of soil and groundwater Cleanup of contaminated soil to prevent direct exposure to the public Cleanup of contaminated ...
 
...direct exposure to the public Cleanup of contaminated soil to prevent leaching impacts to groundwater When remedial alternatives for source control actions are developed, the remedial ...
 
...and, as necessary, institutional controls. 16.2.2.4 Groundwater Remedial Actions Analysis of remedial alternatives for groundwater contamination must ...
 
...Remedial Actions Analysis of remedial alternatives for groundwater contamination must assess varying restoration time periods utilizing different cleanup technologies. ...
 

16.4 Implementing the Cleanup Remedy Selected
...remedial design prior to remedial action implementation. In some cases, such as at groundwater cleanup sites, once the remedial system has been constructed and installed, it may operate ...
 
...generated at sites where long-term cleanup or monitoring activities are planned, such as groundwater treatment and monitoring, or periodic inspections of engineered controls such as soil caps. ...
 

18.4 Common Report Elements
... Climate Soils/Geology/Hydrology Surface Water Groundwater (including location of drinking water and other known wells on or near to the site) ...
 

18.5 Document Outlines
... Actual or probable release to groundwater that is a drinking water supply   ...
 
... 2.1.4 Groundwater   ...
 
... 5.2 Groundwater Sampling Activities   ...
 
... 2.1.4 Groundwater   ...
 
... 5.2 Groundwater Sampling Activities   ...
 
... 6.2 Analytical Results of Groundwater Samples   ...
 
... 2.1.4 Groundwater   ...
 
... 5.3 Groundwater Investigation   ...
 
... 6.3 Groundwater Sampling Procedures   ...
 
... 2.1.4 Groundwater   ...
 
... 5.4 Groundwater Sampling Activities   ...
 
... 7.3 Groundwater Sampling Observations   ...
 
... 8.1.3 Groundwater Samples   ...
 
... 9.3  Groundwater Sampling Analytical Results   ...
 
... 10.3 & Groundwater   ...
 
... document Evaluation of Environmental Hazards at Sites with Contaminated Soil and Groundwater (HDOH, 2008) for a detailed discussion of Environmental Hazard Evaluation. A suggested outline ...
 
... 2.1.4 Groundwater   ...
 
... 9.3 Targeted Tier 1 Groundwater EALs   ...
 
... 9.4 Comparison of Selected Groundwater EALs to Site Data   ...
 
... 2.1.4 Groundwater   ...
 
... 2.1.4 Groundwater   ...
 
... 5.5 Groundwater Sampling Activities   ...
 
... 2.1.4 Groundwater   ...
 
... 6.2 Groundwater Sampling Activities   ...
 
... 9.0 Soil and Groundwater Management for Future Site Activities Affecting On-Site Contamination ...
 
... 9.2 Pre-Excavation Evaluation of Soils and Groundwater   ...
 
... 9.6 Groundwater Handling   ...
 
... 9.7 Groundwater Disposal 10.0 ...
 

18.6 Supporting Forms and Other Documents
...6, Figure 6-7. 18.6.3 Monitoring Well Abandonment Form A groundwater monitoring well that is no longer needed, sustains damage, or is determined to be improperly ...
 
... Owner Information Well Construction Information, including installation date, depth to groundwater, casing and screening material, etc. General Abandonment Information, including ...
 

Contents
... Long-Term Management of Petroleum-Contaminated Soil and Groundwater   ...
 

19.1 Site Closure Scoping
...implications include: Will the remedy restrict future land (or groundwater) use at the site? Will stakeholders concur with the land use restrictions? Will current ...
 
...prospective purchasers in future real estate transactions if contaminated soil and/or groundwater remains on site? What will be the long-term costs of institutional and engineering controls ...
 
...effective in preventing future site occupants from digging into contaminated soil or groundwater? What potential legal liabilities may be caused by managing contaminated soil or ...
 
... What potential legal liabilities may be caused by managing contaminated soil or groundwater on site? Are landowners and other stakeholders willing to accept those liabilities? ...
 

19.3 Closures with Use Restrictions
...applied in situations where representative contaminant levels are above the soil or groundwater "residential use" EALs, but below applicable "commercial/industrial use" EALs at a site zoned ...
 

19.4 No Further Active Remediation Letter
...conditions of further work when (or if) the site is redeveloped. The need for on-going groundwater monitoring or soil gas monitoring may indicate a No Further Active Remediation Letter is not ...
 
...is presented in HDOH guidance on Long-Term Management of Petroleum-Contaminated Soils and Groundwater (HDOH, 2007c; included as Appendix 19-A). This document outlines procedures for ...
 

19.6 Environmental Hazard Management Plan
... capping of contaminated soil to prevent exposure or leaching, or long-term monitoring of groundwater, etc. The EHMP must include the following at a minimum (also see Section ...
 
... Clear depiction of the extent and magnitude of remaining contamination in soil, groundwater and/or soil gas, presented on easily readable, to-scale maps with a north arrow ...
 
...environmental hazards Requirements for long-term monitoring of contaminants in soil, groundwater, and/or soil gas Discussion of engineering and/or institutional controls needed ...
 
...pathways Guidance on proper handling, reuse and disposal of contaminated soil and/or groundwater that is encountered during future site activities Specific description of construction ...
 

19.7 Institutional and engineering Controls
...measures include: Prohibition on excavation of soil Prohibition on use of groundwater Prohibition on residential or other sensitive land use HDOH's primary ...
 
... unlined borrow pits may be adequate for on-site management. Groundwater Contamination Hydraulic Containment � measures are used to control the hydraulic gradient ...
 
...� measures are used to control the hydraulic gradient to minimize the spread of a groundwater plume. One example is the use of pumping wells to actively prevent the plume from spreading ...
 
...permeability materials, such as grout, are injected into the subsurface to contain a groundwater plume. Institutional controls are necessary to restrict groundwater use. Alternative ...
 
... plume. Institutional controls are necessary to restrict groundwater use. Alternative Water Source � an alternative water source can be provided to an area ...
 
...Water Source � an alternative water source can be provided to an area where groundwater is contaminated and not suitable for ingestion. Institutional controls are necessary to ...
 
...and not suitable for ingestion. Institutional controls are necessary to restrict groundwater use. Sediment Contamination Capping systems - contaminated sediments ...
 

Log of TGM Updates
... 6 Groundwater and Surface Water Sampling Guidance Dec 31, ...
 
... Screening for Environmental Hazards at Sites with Contaminated Soil and Groundwater Feb 2005 ...
 

PDF Download Page
... Section 6 - Groundwater and Surface Water Sampling Guidance ...
 
... Appendix 19-A - Long-Term Management of Petroleumcontaminated Soil and Groundwater 231kb ...
 
... Long-term Management of Petroleum-Contaminated Soil and Groundwater. 161kb ...
 

Additional Guidance Documents" Language="VB" MasterPageFile="~/lib/Content.master
... and estimate contaminant concentration in source area leachate and in groundwater. Refer to April 12, 2007 guidance on "Use of Laboratory ...
 
... Soil: Guidance for assessing the potential impact to groundwater posed by leaching of contaminants from vadose-zone soils. This model uses site-specific ...
 
...estimate contaminant concentrations in soil leachate and future impacts to groundwater based on leachate dilution assumptions. See October 2008 ...
 
... Screening for Environmental Hazards at Sites with Contaminated Soil and Groundwater (or "EHE Guidance"). The HEER Office EHE Guidance and HEER Office TGM are the two ...
 
... Environmental Action Levels for Soil, Soil Gas, and Groundwater Environmental Action Levels Surfer (electronic lookup tables) ...
 
...direct exposure, vapor intrusion, leaching and contamination of groundwater, impacts to drinking water resources, impacts to aquatic and terrestrial ...
 

7.10 Documentation of Soil Vapor or Indoor Air Sampling
... the magnitude and nature of subsurface contamination (e.g., free product on shallow groundwater), concentrations of targeted VOCs in source area and subslab soil vapor samples, presence or ...
 

7.10 Documentation of Soil Vapor or Indoor Air Sampling
...In general, passive sample collectors should be deployed as near to the suspected soil or groundwater source as possible in order to reduce the chance of placing the sampler in a pocket ...
 

7.10 Documentation of Soil Vapor or Indoor Air Sampling
...of petroleum fuels, including diesel and other middle distillate fuels. Unlike soil or groundwater, reporting of TPH compounds as �gasoline-range� or �diesel-range� is not applicable to soil ...
 
...level (see also Volume 1 of the EHE guidance). Do soil or groundwater analytical results, or other field data, indicate that concentrations of chemicals ...
 

7.10 Documentation of Soil Vapor or Indoor Air Sampling
...vapor concentrations significantly higher than would otherwise be predicted by soil or groundwater data, see HDOH 2011): Unidentified source in nearby, vadose-zone ...
 
...in vapor phase (e.g., PCE vapors in dry soil beneath slab of a dry cleaner); Groundwater source area closer than ten feet from soil vapor sample point (default depth to water table ...
 
...from discrete samples is very low; see Section 4); Non-representative groundwater data (e.g., heterogeneous plume with isolated �hot spots� nearby); or Relict vapor ...
 
... Relict vapor plume associated with earlier migration of more heavily contaminated groundwater through area in past or post remediation of groundwater contamination. ...
 
...through area in past or post remediation of groundwater contamination. The heterogeneity of contaminants in groundwater plumes has not ...
 
...contamination. The heterogeneity of contaminants in groundwater plumes has not been studied in detail. Heterogeneity can be expected to be significantly greater ...
 
...among others: Source area size and volume (e.g., free product on groundwater >100m2 in area and/or >10m3 contaminated soil present; refer to HDOH 2007c); ...
 
...to HDOH 2007c); Mass of VOCs present in the source media (e.g., soil or groundwater) and associated volume of contaminated soil necessary to sustain long-term, vapor emissions ...
 
...are associated with a relatively small source area of petroleum-contaminated soil or groundwater. In contrast, measures to eliminate potential vapor pathways might be required at a site where ...
 
...regardless of the absence of clear impacts to existing buildings if source area soil, groundwater and/or soil vapor data suggest potential future vapor intrusion risks or other environmental ...
 
...the HDOH technical memorandum Long-Term Management of Petroleum-Contaminated Soil and Groundwater (HDOH 2007c). As a general rule a home or building should not be flagged for potential ...
 
...and within the limitations described in the EHE document (HDOH 2011), VOCs in groundwater or soil vapor below the corresponding Tier 1 EALs can be assumed to not pose a significant ...
 

7.10 Documentation of Soil Vapor or Indoor Air Sampling
...soil vapor or indoor air sampling locations. The relative location of soil and groundwater contamination with respect to locations of sampling probes and all current or proposed future ...
 

13.6 Ecological Risk assessements
... for each environmental medium (e.g., COPCs for soil may be different that the COPCs for groundwater). The identified list of COPCs will be the focus of the HHRA. 13.7.1.2 EXPOSURE ...
 

Appendices
... Long-Term Management of Petroleum-Contaminated Soil and Groundwater.   ...
 

Appendix 19-A Long-Term Management of Petroleum-Contaminated Soil and Groundwater
... APPENDIX 19-A Long-Term Management of Petroleum-Contaminated Soil and Groundwater.   (see PDF file) ...
 

9.6 Methamphetamine Laboratory Cleanup
...building if residues enter the heating, ventilation and air-conditioning system. Soil or groundwater may become contaminated if chemicals are disposed of in a septic system or dumped outside. ...
 

Appendix 9-B Initial Shortlist of Pesticides Used in Sugarcane and Pineapple Operations
... 1 Montgomery, J.H. 2000. Groundwater Chemicals. Desk Reference (3rd Ed). ...
 
... 8 Knisel & Davis. 2000. Groundwater Loading Effects of Agricultural Management Systems. ...
 

Appendix 9-D Guidance Fact Sheet for Use When Petroleum Contamination is Encountered
...surface water, or any navigable water of the State. Any free product that appears on groundwater. Any amount of oil released to the environment greater than 25 gallons. Any ...
 
...Office (808) 586-4249 during business hours for assistance. Groundwater Management: Groundwater that contains free product or a sheen can ...
 
...Management: Groundwater that contains free product or a sheen can assumed to be contaminated with dissolved ...
 
...disposal, or discharge are all acceptable options for the disposition of groundwater generated during subsurface excavation that encounters contaminated groundwater. Of ...
 
...generated during subsurface excavation that encounters contaminated groundwater. Of these choices, re-infiltration within the Work Area where the water was extracted ...
 
...water was extracted is the least expensive and easiest way to manage contaminated groundwater; however this option may not be feasible at all project locations. ...
 
...feasible at all project locations.   Groundwater should be reused within the Work Area and within the same aquifer where it ...
 
... At a minimum, all groundwater discharged to storm sewers must be analyzed for constituents ...
 
... the vicinity of the work area. The groundwater must be analyzed for known or suspected contaminants and the results ...
 
...Hazards at Sites with Contaminated Soil and Groundwater, Fall 2011 Updates, Revised January 2012 (and updates) For some ...
 
... The trench must be within the Work Area, especially if the groundwater is extracted from a Work Area in the vicinity of known or observed ...
 

5.10 Investigation Derived Waste
...with detergent/wash water mixes avoided. Management and disposal of waste groundwater generated during developing and purging activities is discussed in Section 6 and summarized ...
 
...immediately downgradient of the well provided that it is generated from the uppermost groundwater unit, is not impacted above action levels applicable to the site, does not contain free product ...
 

8.5 Field Screening With Cone Penetrometer and Sensors/Probes
...deploy. The devices developed for these platforms are: samplers for soil, soil gas and groundwater; geotechnical sensors for soil texture and hydraulic conductivity; and chemical sensor sampling ...
 
...with grain size but also with soil water content and ionic strength of the pore water or groundwater. Ionic strength of the groundwater can change due to contaminant content. Dense non-aqueous ...
 
...Ionic strength of the groundwater can change due to contaminant content. Dense non-aqueous phase liquids (DNAPL) have a very ...
 
...can be used to determine the hydraulic conductivity of subsurface soils and the depth to groundwater. These data can be used to identify potential contaminant pathways in the subsurface, or to ...
 
...Hydrosparge™ systems for the detection of volatile organic compounds in soil and groundwater (USEPA 2004 and 2005). USEPA evaluation of chemical sensors used with CPT has ...
 
...a method for real-time, in situ, field screening of hydrocarbons in subsurface soil and groundwater. The technologies are intended to provide highly detailed, qualitative to semi-quantitative ...
 
...heat to volatilize and mobilize contaminants for sampling. Heating the soil and/or groundwater adjacent to the MIP�s semi-permeable membrane volatilizes the VOCs, which then pass ...
 
...near the membrane to 80 to 125 �C (160 to 232 �F), which allows VOCs in the soil and groundwater to partition across the membrane in saturated or unsaturated soil. The subsurface temperature ...
 
... in the soil�s electrical behavior that can be related to changes in stratigraphy or groundwater quality. Analytical devices commonly used with an MIP include gas chromatography (GC)-grade ...
 
...provide screening-level data that need to be supplemented with analytical soil or groundwater data to fully support human health risk assessments or remediation decisions. ...
 

8.6 Field Screening Equipment to Support Health and Safety Programs
...instruments discussed in the following subsections are typically used during soil and groundwater investigations. Additional air monitoring, radiation monitoring or other specialized equipment ...