Draft Guidance on Vapor Intrusion into Buildings from Groundwater and Soil under the Act 2 Statewide Health Standard Vapor Intrusion Subcommittee

Transcription

1 Draft Guidance on Vapor Intrusion into Buildings from Groundwater and Soil under the Act 2 Statewide Health Standard Vapor Intrusion Subcommittee Cleanup Standards Scientific Advisory Board Meeting July 22, 2003

2 ACRONYMS AND ABBREVIATIONS USED IN VAPOR INTRUSION GUIDANCE CERCLA Comprehensive Environmental Response Compensation and Liability Act COPIAC Constituent of Potential Indoor Air Quality Concern HQ Hazard quotient IAQ Indoor Air Quality J&E Model Johnson & Ettinger model MSC Medium specific concentration MSCgw Residential MSC for groundwater MSC IAQ MSC for Indoor Air Quality MSC SG MSC for soil gas MSC soil to gw Soil to groundwater numeric value NAPL Nonaqueous phase liquid OSHA Occupational Safety and Health Administration PEL Permissible exposure level RCRA Resource Conservation and Recovery Act RL Cancer risk level SHS Statewide health standard SPL Separate phase liquid SSS Site-specific standard USEPA U.S. Environmental Protection Agency

3 DEPARTMENT OF ENVIRONMENTAL PROTECTION Bureau of Land Recycling and Waste Management DOCUMENT NUMBER: TITLE: Land Recycling Program Technical Guidance Manual- Section IV.A.4. Vapor Intrusion into Buildings from Groundwater and Soil under the Act 2 Statewide Health Standard. ANTICIPATED EFFECTIVE DATE: October 26, 2002 AUTHORITY: The Land Recycling and Environmental Remediation Standards Act (Act 2 of 1995) (35 P.S et seq.) and the regulations issued pursuant to that legislation at 25 PA Code Chapter 250. POLICY: It is the policy of the Department to implement Act 2 in accordance with the regulations contained in Chapter 250 of the PA Code and as described in this guidance manual. PURPOSE: The Department has developed a technical guidance manual to assist remediators in satisfying the requirements of Act 2 and the regulations published in Chapter 250 of the PA Code. This specific guidance, which is to be incorporated into the technical manual, is to provide additional attainment screening requirements in some cases, to prevent risk of unacceptable risk being present as result of vapor intrusion of contaminants from soil and/or groundwater into indoor structures. APPLICABILITY: The guidance is applicable to any person or persons conducting a site remediation under Act 2 under the Statewide Health Standard. DISCLAIMER: The policies and procedures outlined in this guidance document are intended to supplement existing requirements. Nothing in the policies or procedures will affect regulatory requirements. The policies and procedures herein are not an adjudication or a regulation. There is no intent on the part of the Department to give these rules that weight or deference. This document establishes the framework, within which DEP will exercise its administrative discretion in the future. DEP reserves the discretion to deviate from this policy statement if circumstances warrant. PAGE LENGTH: pages LOCATION: Volume 5 Tab 32 DEFINITIONS: See 25 Pa. Code Chapter / DRAFT /Page 1

4 Introduction When releases occur near buildings, volatilization of organic contaminants from the dissolved or pure phases in the subsurface can result in the intrusion of vapor-phase contaminants into indoor air. Indoor air quality (IAQ) from the vapor intrusion of contaminants into buildings from groundwater and soil is not specifically detailedassessed under the Statewide Health Standard (SHS) in the Act 2, Chapter 250 regulations. This document provides guidance for assessing potential subsurface vapor intrusion of volatile organic and semivolatile contaminants into buildings from contaminated groundwater and soils under SHS. However, it is important to note that the use of this Guidance is not mandated. The responsible party may choose to use a site-specific approach (including site-specific modeling and/or sampling) or to mitigate the situation at any time. It should be noted that ifthis section provides guidance for assessing vapor intrusion under the SHS. Remediators a remediator wisheswho choose to forgo the sampling activities outlined in this guidance document, they may proceed directly to a sitespecific analysis (which may also ultimately require some limited IAQ sampling) or alternatively they may proceed directly to mitigation without either of these analyses. If volatile inorganic constituents are of concern (i.e., mercury, ammonia, cyanide) the remediator may address them under the site-specific standard. Decision matrices for consideration of indoor air quality were developed for groundwater and soil under a Statewide health or generic approach. The matrices apply under the specific conceptual model conditions used in their development. Hence, users are cautioned to make sure that the conditions at the site are applicable. In these decision matrices for soil and groundwater, several options are provided for determining if IAQ is a concern. Any one or more of these options may be undertaken in order to assess IAQ issues. These include: Comparison of media concentration to previously available soil and groundwater medium specific concentrations (MSCs). This option allows one a remediator to determine when a constituent is not of potential concern for indoor air if certain available MSCs are met (see Tables 1-2, Groundwater; Tables 4-5, Soil). Specifically, with the exception of some volatile compounds, none of the regulated substances for which a nonuse aquifer standard is listed in Chapter 250 would be a concern in groundwater if the MSCs for nonuse aquifers are met. The same is true for soil meeting a used aquifer standard, with some regulated substances being a concern at levels below the used aquifer standards published in Chapter 250. Although the currently available MSCs have their specific points of compliance (e.g., GW at the property boundary) use of the MSC for the vapor intrusion pathway must meet the applicable conditions for the pathway (e.g., within 100 of an occupied building). Comparison of media concentration to conservative default screening values for groundwater and soil (see Tables 1-2 and Tables 4-5) calculated using / DRAFT /Page 2

5 Pennsylvania-specific parameters and the Johnson and Ettinger (J&E) Vapor Intrusion model (USEPA, 2001). These values are used to identify chemicals of potential indoor air concern (COPIACs) when this calculated screening level is lower than an MSC. However, the values can also be used to screen the concentration of COPIACs in a given medium to determine if additional evaluation or mitigation is warranted. For example, the residential screening value for chloroform in groundwater is 410 µg/l (see Table 1). Based on this value, groundwater concentrations that meet the used aquifer MSC would not be of concern for the indoor air pathway. However, concentrations above 410 µg/l (including groundwater that meets the nonuse aquifer MSC) would require further evaluation. Note this option is available even if the constituent is identified as a COPIAC. Comparison of media concentration to soil gas values derived using the MSC IAQ and a transfer factor to account for attenuation between the outside and inside of buildings. This allows one a remediator to measure vapor concentrations outside the buildings and extrapolate to estimated levels inside the building. See Table 3. Comparison of media concentration to MSC developed for IAQ (MSC IAQ ) using measured indoor air concentrations. See Table 3. If indoor air quality is determined to be a concern based on the use of these matrices, one may address (mitigate) the contamination or perform a site-specific evaluation. General Considerations There are basically two prerequisites conditions that must be met for the vapor intrusion pathway to be of potential concern. First, inhabited buildings must be close to a volatile/semivolatile source and, second, the source concentration must be above some threshold or screen concentration. Through a series of modeling exercises and professional judgment these conditions were incorporated into the guidance. Table 9 provides values for chemical, physical and toxicological properties that were used in modeling to derive screening values. The distance at which concentrations are negligible is a function of the mobility, toxicity and persistence of the chemical, as well as the geometry of the source, subsurface materials, and characteristics of the building of concern. A horizontal distance of 100 feet from the source to receptor (inhabited building) was chosen as the criterion to define when sites were close enough and so needed to be addressed for vapor intrusion. Vertical separation distances, based on the modeling exercises, are discussed in later sections of the Guidance. Screening values were also defined on the basis of the modeling exercise and are discussed in appropriate sections. In addition, under SHS, if separate phase liquid (SPL see definitions) is encountered beneath the structure or within 100 feet of the receptor, then the model-derived values should not be used. The model used does not account for SPL. Instead, sampling of soil gas (recommended) or indoor air is required to meet SHS. Alternatively, use of the / DRAFT /Page 3

6 J&E model with the non-aqueous phase liquid (NAPL) component on a site-specific modeling basis may be considered. The presence of preferential exposure pathways (see definitions) within 30 feet of the source also limits the further use of the matrix, i.e., the model used to develop default screening levels cannot account for preferential pathways. In this case, not only is It is not possible to predict contaminant concentrations but it is not possiblenor to determine where the material will end up. Hence, sampling is required to meet SHS if preferential pathways are present. Evaluating the vapor intrusion pathway into buildings, on a generic basis, is extremely difficult. For example, even though reasonable Pennsylvania-specific assumptions (Table 8) were used, the J&E model as applied uses conservative processes (e.g., infinite source, no degradation). This tends to produce conservative screening values that may indicate a potential IAQ problem where there is not one. It was decided to err on the side of conservatism, since the option exists to further evaluate on a more site-specific basis if believed warranted. Another important concern is the prevalence of other sources of volatile organics (particularly indoors) that can complicate interpretation of sampling results. Several constituents, e.g., benzene and trichloroethylene, have calculated indoor air MSCs that are lower than background levels. A remediator should use caution when making decisions based on both indoor air and soil gas analyses and take these background levels into consideration. EPA s database (USEPA, 1988, Shah and Singh, 1988) is a good source of information on measured indoor and outdoor air background levels. Also, the New York Department of Health recently is developed developing a compilation including the EPA database values and values measured in New York (NYDOH, 2003) State. If a property does not currently have occupied buildings or structures containing enclosed spaces that could retain vapors and it is possible that future development will consist of occupied buildings or structures containing enclosed spaces (residential or nonresidential), the deed acknowledgment requirements shall apply pursuant to Chapter (g). Application To the Site-Specific Standard The development of the indoor air-specific concentrations (MSC iaq ) for volatile chemicals under the Statewide health standard (SHS) has been entirely focused on the individual chemicals. No pre-planned effort was made to address the cumulative effects of the chemicals under the SHS, consistent with Act 2. The reason for this is that the process used to develop the indoor air MSC is so highly conservative. For example, the maximum acceptable risk level under Act 2 that is employed in the site-specific standard (SSS) is The MSCs intended for use in the SHS were derived using a potential cancer risk of It is apparent here that there is a 10-fold additional factor of protectiveness in this aspect of the derivation alone. For the reasons of sufficient conservatism already incorporated, additional consideration of cumulative indoor air effects in the SHS is considered unwarranted, again consistent with Act / DRAFT /Page 4

7 For the SSS, it is appropriate to use a similar screening process as used to identify potential indoor air concerns at the Statewide health standardshs. This is consistent with the purpose of the screening, which is to eliminate chemicals from quantitative consideration if they are present at concentrations that clearly do not pose a potential for unacceptable risk. However, additional considerations are warranted for the indoor air pathway (as for all pathways) under the SSS. The cumulative effects of chemicals, which are present at concentrations exceeding their respective indoor air MSCs are considered in the SSS by summing those potential risks for each receptor from all appropriate chemicals (separately for both cancer and non-cancer effects) and pathways. This methodology is consistent with standard USEPA approaches under the RCRA and CERCLA programs. Also under the SSS, the intrusion pathway from groundwater to indoor air cannot be considered as incomplete based on the groundwater screen-out criterion. The groundwater criterion says that the inhabited building or structure is separated vertically from the source by at least five feet of soil-like material (see SHS definitions). The intrusion pathway from soil to indoor air also cannot be used as a screen-out criterion. The soil screen out criterion says that the inhabited building is separated vertically from the source by at least five feet of soil-like material. These two screenout criteria in the IAQ decision matrices for SHS are not available under the SSS. These two criteria were developed based on the assumption that the site would meet all other requirements of the SHS prior to consideration of the screen out criteria. Hence, these assumptions are not valid under the SSS. Process for Groundwater In the Groundwater IAQ Decision Matrix for SHS (Figure 1), the receptor location and type of soil are critical. The pathway is only relevant if inhabited buildings are proximate to the source. Further, under SHS, if SPL (SPL see SHS definitions) is encountered beneath the structure or within 100 feet of the receptor at or above the water table, the matrix should not be used. Instead, sampling of soil gas (recommended) or indoor air is required for meeting a SHS, or a site-specific evaluation (including optional site-specific modeling) should be considered. In addition, the presence of preferential exposure pathways (see SHS definitions) limits the further use of the matrix. Hence, additional sampling is required to meet the SHS if preferential exposure pathways are present and pass through the source or occur within 30 feet of the source. For situations where a subsurface vapor source is within 100 feet of an occupied building, several options are available to determine if a potential pathway exists. For each constituent, one may choose one or more options, as appropriate, to determine whether further evaluation or mitigation is needed. Failure to meet this generic evaluation indicates that a pathway may exist and further site-specific evaluation or mitigation is warranted. Options are: For residential land uses, if the COPIAC (see SHS definitions) levels of chlorodibromomethane, chloroethane, chloroform, 1,1-dichloroethylene, ethylbenzene, naphthalene, 1,1,1,2-tetrachloroethane, 1,2,3-trichloropropane, / DRAFT /Page 5

8 and xylenes do not exceed the residential groundwater MSC (MSCgw) for used aquifers, and other regulated substances in groundwater do not exceed the residential MSCgw for a nonuse aquifer, no further site evaluation is required. Note: the receptor must be separated vertically from the source by at least 5 five feet of soil-like material. If the material below the receptor is predominantly sand, the require vertical separation may need to be greater than 5 five feet and the derived values should not be used without further site-specific model evaluation. See Table 1 for groundwater residential values. For nonresidential land uses, if the COPIAC levels of benzotrichloride, chlorodibromomethane, chloroethane, chloroform, ethylbenzene and 1,2,3- trichloropropane do not exceed the nonresidential MSCgw for used aquifers and other regulated substances do not exceed the nonresidential MSCgw for nonuse aquifers, no further site evaluation is required. Note: the receptor must be separated vertically from the source by at least 5 five feet of soil-like material. If the material below the receptor is predominantly sand, the require vertical separation may need to be greater than 5 five feet and the derived values should not be used without further site-specific model evaluation. No regulated substances were identified as being of concern when Occupational Safety and Health (OSHA) endpoints (i.e., permissible exposure limits or PELs) were used with standard worker exposure assumptions, when the source and receptor are separated vertically by at least 5 five feet of soil-like material except as noted for sand above. The OSHA-derived screen (PA defaults) may be used as an alternate to the default EPA-derived screen when OSHA regulations are fully implemented (e.g., notification, monitoring) and documented in a workplace building. In addition, the permissible exposure limits (PELs) prescribe concentrations that cannot be exceeded during a workday. See Table 2 for groundwater nonresidential values. If the groundwater concentrations are is less than the J&E PA default screening levels (Table 1 residential, Table 2 nonresidential) and the groundwater is greater than or equal to 5 five feet from the receptor, then no further IAQ activity for groundwater is required. This option may be used regardless of whether the constituent is identified as a COPIAC or not. If the material below the building is predominately sand or sand-like material, the derived values should not be used and therefore soil gas (recommended) or indoor air sampling should be done. Sand-like material is defined as a conglomeration of residuals that are similar to sand and have the same characteristics and properties as sand (i.e. foundry sand, ash). Soil-like material is defined as a conglomeration of soils that are similar to and have the same characteristics and properties as soil. Note: When screening groundwater concentrations, the decision to proceed in the screen is based on a non-exceedance rule, NOT the use of the 75%/10x rule. If the measured soil gas concentration is less than or equal to the soil gas MSC (MSC SG - see SHS definitions), then no further IAQ activity for groundwater is required. These values are found in Table 3. The MSC SG (see SHS definition - soil gas) is a function of the MSC IAQ and a transfer (or attenuation) factor of 0.01, applies in going from outside to inside the building / DRAFT /Page 6

9 If the measured indoor air concentration is less than or equal to the indoor air MSC (MSC IAQ ), then no further IAQ activity for groundwater is required. These values are found in Table 3. If none of the generic options are met, then risk management (mitigation) activities may be warranted, including another comparison to MSC IAQ of either soil gas or measured indoor levels after mitigation. However, one may proceed to a site-specific risk analysis (including using the J&E model with site-specific input) in lieu of additional efforts under SHS. If MSC SG or MSC IAQ is not exceeded, then no further IAQ activity for groundwater is warranted. Process for Soil In the Soil IAQ Decision Matrix for SHS (Figure 2), the receptor location and type of soil are critical. The pathway is only relevant if inhabited buildings are proximate to the source. Further, if SPL is encountered beneath or within 100 feet of an inhabited building or below grade occupied space at or above the water table, the matrix should not be used. Instead, sampling of soil gas (recommended) or indoor air is required for meeting a SHS, or a site-specific evaluation (including optional site-specific modeling) should be considered. Also, if preferential exposure pathways are present and pass through the source or occur within 30 feet of the source, then the decision matrix requires that soil gas (recommended) or indoor air sampling be performed. For situations where a subsurface vapor source is within 100 feet of an occupied building, several options are available to determine if a potential pathway exists. For each constituent, one may choose one or more options, as appropriate, to determine whether further evaluation or mitigation is needed. Failure to meet this generic evaluation, indicates that a pathway may exist and further site-specific evaluation or mitigation is warranted. Options are: The following chemicals were identified as COPIACs because their presence in soil even below the MSC soil to gw for used aquifers may lead to indoor air concerns. However, it should be noted that there is considerable uncertainty with evaluating soil concentrations on a generic basis and this guide has intentionally erred on the conservative side to include rather then exclude constituents as COPIACs. Soil gas concentrations are a useful alternative to bulk soil concentrations for evaluating the soil medium. A remediator must sample and analyze for those constituents pertaining to the particular release at the site that are on the COPIAC list or in Tables 1, 2, Table 10, or on Tables 4, and 5. If the volatile organic constituent is not listed in the tables and it is found to be a concern at a particular site, then a site-specific analysis should be used. The COPIACs identified in soil based on specific receptors are as follows: The chemicals on Table 10 were identified as COPIACs because their presence in soil at levels below the MSC soil to gw for used aquifers may lead to indoor air / DRAFT /Page 7

10 concerns. However, it should be noted that there is considerable uncertainty with evaluating soil concentrations on a generic basis and this guide has intentionally erred on the conservative side to include rather then exclude constituents as COPIACs. Soil gas concentrations are a useful alternative to bulk soil concentrations for evaluating the soil medium. If any of these COPIACs are present at the site, then further generic (e.g., comparison to default J&E values or soil gas measurement) or site-specific (including site-specific modeling) evaluation is needed. However, one may choose to mitigate at any time. If non-copiac volatile constituents do not exceed the MSC soil to gw (Tables 4 & 5) for a used aquifer, no further IAQ activity for soil is required. Note: the receptor must be separated vertically from the source by at least five feet of soil-like material. If the material below the receptor is predominantly sand or sand-like material, the required vertical separation may need to be greater than five feet and the derived values should not be used without further site-specific model evaluation. For a potentially complete exposure pathway, if the soil concentrations are less than the J-E PA default screening levels (Table 4 residential, Table 5 nonresidential) and the contamination is greater than or equal to five feet from the receptor, then no further IAQ activity for soil is required. This option may be used regardless of if the constituent is identified as a COPIAC or not. If the material below the building is predominately sand or sand-like material, the derived values should not be used and therefore soil gas (recommended) or indoor air sampling should be done. Sand-like material is defined as a conglomeration of residuals that are similar to sand and have the same characteristics and properties as sand (i.e. foundry sand, ash). Soil-like material is defined as a conglomeration of soils that are similar to and have the same characteristics and properties as soil. Note: When screening soil concentrations, the decision to proceed in the screen is based on a nonexceedance rule, NOT the use of the 75%/10x rule. If the measured soil gas concentration is less than or equal to the soil gas MSC (MSC SG ), then no further IAQ activity for soil is required. If the measured indoor air concentration is less than or equal to the indoor air MSC (MSC IAQ ), then no further IAQ activity for soil is required. These values are found in Table 3. The OSHA-derived screen (PA defaults) may be used when OSHA regulations are fully implemented and documented in a workplace building. In addition, the permissible exposure limits (PELs) would also prescribe concentrations that cannot be exceeded during a workday. If none of these generic options is met, then risk management (mitigation) activities may be warranted, including another comparison to MSC IAQ of either soil gas or measured indoor levels after mitigation. However, one may proceed to a site-specific risk analysis (including using the J&E model with site-specific input) in lieu of additional efforts / DRAFT /Page 8

11 under SHS. If MSC SG or MSC IAQ is not exceeded, then no further IAQ activity for soil is warranted / DRAFT /Page 9

12 If any of these COPIACs are present at the site, then further generic (e.g., comparison to default J&E values or soil gas measurement) or site-specific (including site-specific modeling) evaluation is needed. However, one may choose to mitigate at any time. If non-copiac volatile constituents do not exceed the MSC soil to gw (Tables 4 & 5) for a used aquifer, no further IAQ activity for soil is required. Note: the receptor must be separated vertically from the source by at least 5 feet of soil-like material. If the material below the receptor is predominantly sand, the required vertical separation may need to be greater than 5 feet and the derived values should not be used without further site-specific model evaluation. For a potentially complete exposure pathway, if the soil concentrations are less than the J-E PA default screening levels (Table 4 residential, Table 5 nonresidential) and the contamination is greater than or equal to five feet from the receptor, then no further IAQ activity for soil is required. This option may be used regardless of if the constituent is identified as a COPIAC or not. Note: When screening soil concentrations, the decision to proceed in the screen is based on a non-exceedance rule, NOT the use of the 75%/10x rule. If the material below the building is predominately sand or sand-like material, the derived values should not be used and therefore soil gas (recommended) or indoor air sampling should be done. Sand-like material is defined as a conglomeration of residuals that are similar to sand and have the same characteristics and properties as sand (i.e. foundry sand, ash). Soil-like material is defined as a conglomeration of soils that are similar to and have the same characteristics and properties as soil. If the measured soil gas concentration is less than or equal to the soil gas MSC (MSC SG ), then no further IAQ activity for soil is required. These values are found in Table 3. MSC SG (see SHS definition - soil gas) is a function of the MSC IAQ and a transfer (or attenuation) factor of 0.01, from outside to inside the building. If the measured indoor air concentration is less than or equal to the indoor air MSC (MSC IAQ ), then no further IAQ activity for soil is required. These values are found in Table 3. The OSHA-derived screen (PA defaults) may be used when OSHA regulations are fully implemented and documented in a workplace building. In addition, the permissible exposure limits (PELs) would also prescribe concentrations that cannot be exceeded during a workday. If none of these generic options is met, then risk management (mitigation) activities may be warranted, including another comparison to MSC IAQ of either soil gas or measured indoor levels after mitigation. However, one may proceed to a site-specific risk analysis / DRAFT /Page 10

13 (including using the J&E model with site-specific input) in lieu of additional efforts under SHS. If MSC SG or MSC IAQ is not exceeded, then no further activity for soil is warranted. Sampling For either matrix under SHS, the presence of SPL requires sampling of either soil gas or indoor air at the location of the receptor for levels of regulated substances that may be present. In addition, the existence of preferential exposure pathways (see SHS Definitions) moves the process to sampling. Approaches for soil gas screening and interpretation and IAQ sampling and interpretation are listed briefly in Table 6. Note that when sampling indoor air, many regulated substances have multiple sources and may be present in indoor air due to outdoor ambient levels or sources within the building rather than due to presence in groundwater or soil (e.g., benzene, chloroform). These constituents are identified on Table 3. Sources are found in a variety of household products such as paints, fuels, varnishes and cleaning solutions, from personal habits (e.g., smoking) or hobbies (e.g., glues and adhesives). Use caution in taking indoor air samples and interpreting the results in this context. Sampling soil gas and indoor air is complex and should be approached with caution. A plan should be developed to assist in addressing data quality objectives before beginning sampling. Odors Odor perception is highly subjective and odors are not directly always an indication of a human health concern. Odor was evaluated during the development of the MSC IAQ because some substances can be detected by odor (odor threshold) at low concentrations in air, much lower than those that would cause a health concern. A comparison of the odor thresholds from literature sources to the corresponding MSC IAQ was done. The odor thresholds of approximately 1210% of the compounds listed on Table 3 are lower than the residential MSC IAQ. Because there is not a substantial difference between the odor thresholds and MSC IAQ, odors were not considered further in the IAQ scheme under SHS (Table 3) / DRAFT /Page 11

14 Pre-Screen Site: Determine if the vapor intrusion pathway is applicable and if the matrix should be used NO START YES Is SPL present at or above water table? YES Is Subsurface contamination within 100 feet of an inhabited building? YES Do preferential pathways exist? YES Matrix should not be used. Continue evaluation with (A) or (B). YES, No SPL or Preferential Path Determine if a potential pathway exits: Several options available YES YES YES YES YES For each constituent, evaluate against any appropriate option & continue Is MSC GW (used aquifer) met for COPIACs (Tables 1 & 2) and 5 feet of soil-like* material? Is MSC GW (non-used aquifer) met for non-copiacs (Tables 1 & 2) and is contamination at 5 feet of soil-like* material? Is an appropriate J& E screening level met (Tables 1 & 2) and is contamination at 5 feet of soil-like* material? Is soil gas concentration screening level (100 x MSC IAQ )? Is indoor air concentration MSC IAQ? NO NO NO NO NO Next Steps for potentially complete pathways: Continue generic evaluation (A) or address IAQ (B) A or B A or B A or B A or B (A) Perform soil gas (recommended) or indoor air measurement, if the pathway cannot be eliminated using any of the available generic evaluation options Is MSC IAQ Met? NO YES Pathway incomplete or presents negligible risk: No further IAQ issues for Groundwater (B) Address IAQ: Perform site-specific analysis or mitigate * If the soil-like material below buildings is predominantly sand or sand-like, the derived values should not be used (see textshs definitions). Figure 1 GW IAQ Decision Matrix for SHS (DRAFT 06/17/03) / DRAFT /Page 12

15 Pre-Screen Site: Determine if the vapor intrusion pathway is applicable and if the matrix should be used Determine if a potential pathway exits: Several options available Next Steps for potentially complete pathways: Continue generic evaluation (A) or address IAQ (B) START YES, No SPL or Preferential Path For each constituent, evaluate against any appropriate option & continue NO YES Is Subsurface contamination within 100 feet of an inhabited building? Is SPL Present at or above water table? YES YES Do preferential pathways exist? YES NO YES YES Are COPIACs (Tables 4 & 5) present? Is an appropriate MSC soil-gw (Tables 4 & 5) met for non- COPIACs and is contamination at 5 feet of soil-like* material? Is an appropriate J& E screening level (Tables 4 & 5) met and is contamination at 5 feet of soil-like* material? YES NO NO A or B A or B A or B (A) Perform soil gas (recommended) or indoor air measurement, if the pathway cannot be eliminated using any appropriate generic evaluation options Matrix should not be used. Continue evaluation using (A) or (B) YES YES Is soil gas concentration screening level (100 x MSC IAQ )? Is indoor air concentration MSC IAQ? NO NO A or B Is MSC IAQ Met? YES NO Pathway incomplete or presents negligible risk: No further IAQ issues for Soils (B) Address IAQ: Perform site-specific analysis or mitigate * If the soil-like material below buildings is predominantly sand or sand-like, the derived values should not be used (see textshs definitions). Figure 2 SOIL IAQ Decision Matrix for SHS (DRAFT 06/17/03) / DRAFT /Page 13

16 CAS Number Table 1 Groundwater Screening Values (µg/l) for Protection of Indoor Air - Residential Regulated Substance Pennsylvania GW MSC Used Aquifer Pennsylvania GW MSC Nonuse Aquifer PA Defaults Residential Volatilization to Indoor Air Screen* ACENAPHTHENE NOC ACENAPHTHYLENE NOC ACETALDEHYDE ACETONE NOC ACETONITRILE ACETOPHENONE NOC ACROLEIN ACRYLAMIDE ACRYLIC ACID ACRYLONITRILE ALLYL ALCOHOL ANILINE ANTHRACENE NOC BENZENE BENZOTRICHLORIDE BENZYL CHLORIDE BIPHENYL, 1, NOC BIS(2-CHLOROETHYL)ETHER BIS(2-CHLORO-ISOPROPYL)ETHER BIS(CHLOROMETHYL)ETHER BROMOCHLOROMETHANE BROMODICHLOROMETHANE BROMOMETHANE BUTADIENE, 1, BUTYL ALCOHOL, N NOC BUTYLBENZENE, N NOC BUTYLBENZENE, SEC NOC BUTYLBENZENE, TERT NOC CARBON DISULFIDE CARBON TETRACHLORIDE CHLORO-1,1-DIFLUOROETHANE, NOC CHLORO-1-PROPENE, 3- (ALLYL CHLORIDE) CHLOROBENZENE CHLOROBUTANE, NOC CHLORODIBROMOMETHANE CHLORODIFLUOROMETHANE NOC CHLOROETHANE CHLOROFORM CHLORONAPHTHALENE, NOC CHLOROPHENOL, CHLOROPRENE CHLOROPROPANE, CHLOROTOLUENE, O CRESOL(S) NOC / DRAFT /Page 14

17 CAS Number Table 1 Groundwater Screening Values (µg/l) for Protection of Indoor Air - Residential Regulated Substance Pennsylvania GW MSC Used Aquifer Pennsylvania GW MSC Nonuse Aquifer PA Defaults Residential Volatilization to Indoor Air Screen* CRESOL, O- (METHYLPHENOL, 2-) NOC CROTONALDEHYDE CROTONALDEHYDE, TRANS CUMENE NOC CYCLOHEXANONE NOC DIBROMO-3-CHLOROPROPANE, 1, DIBROMOETHANE, 1,2- (ETHYLENE DIBROMIDE) DIBROMOMETHANE DICHLORO-2-BUTENE, 1, DICHLOROBENZENE, 1, NOC DICHLOROBENZENE, 1, NA DICHLOROBENZENE, 1, DICHLORODIFLUOROMETHANE (FREON 12) DICHLOROETHANE, 1, DICHLOROETHANE, 1, DICHLOROETHYLENE, 1, DICHLOROETHYLENE, CIS-1, DICHLOROETHYLENE, TRANS-1, DICHLOROMETHANE (METHYLENE CHLORIDE) DICHLOROPROPANE, 1, DICHLOROPROPENE, 1, DICHLOROPROPIONIC ACID, 2, NOC (DALAPON) DICYCLOPENTADIENE DIMETHYLANILINE, N,N DIOXANE, 1, EPICHLOROHYDRIN ETHOXYETHANOL, 2- (EGEE) ETHYL ACETATE ETHYL ACRYLATE ETHYL BENZENE ETHYL DIPROPYLTHIOCARBAMATE, NOC S- (EPTC) ETHYL ETHER ETHYL METHACRYLATE ETHYLENE GLYCOL NOC FLUORENE NOC FLUOROTRICHLOROMETHANE (FREON 11) FORMALDEHYDE FORMIC ACID NOC FURAN / DRAFT /Page 15

18 CAS Number Table 1 Groundwater Screening Values (µg/l) for Protection of Indoor Air - Residential Regulated Substance Pennsylvania GW MSC Used Aquifer Pennsylvania GW MSC Nonuse Aquifer PA Defaults Residential Volatilization to Indoor Air Screen* FURFURAL HEXANE NOC HYDRAZINE/HYDRAZINE SULFATE ISOBUTYL ALCOHOL NOC METHACRYLONITRILE METHANOL METHOXYETHANOL, METHYL ACETATE METHYL ACRYLATE METHYL CHLORIDE METHYL ETHYL KETONE METHYL ISOBUTYL KETONE METHYL METHACRYLATE METHYL STYRENE (MIXED ISOMERS) METHYL TERT-BUTYL ETHER (MTBE) METHYLNAPHTHALENE, NOC METHYLSTYRENE, ALPHA NAPHTHALENE NITROBENZENE NITROPHENOL, NOC NITROPROPANE, NITROSODIETHYLAMINE, N NITROSODIMETHYLAMINE, N NITROSO-DI-N-BUTYLAMINE, N PCB-1221 (AROCLOR) NA PHENANTHRENE NOC PHENOL NOC PROPYLBENZENE, N NOC PROPYLENE OXIDE PYRIDINE STYRENE NOC TETRACHLOROETHANE, 1,1,1, TETRACHLOROETHANE, 1,1,2, TETRACHLOROETHYLENE (PCE) TOLUENE TRIBROMOMETHANE (BROMOFORM) TRICHLORO-1,2, NOC TRIFLUOROETHANE, 1,1, TRICHLOROBENZENE, 1,2, NOC TRICHLOROBENZENE, 1,3, NOC TRICHLOROETHANE, 1,1, NOC TRICHLOROETHANE, 1,1, TRICHLOROETHYLENE (TCE) TRICHLOROPROPANE, 1,1, TRICHLOROPROPANE, 1,2, / DRAFT /Page 16

19 Table 1 Groundwater Screening Values (µg/l) for Protection of Indoor Air - Residential CAS Number Regulated Substance Pennsylvania GW MSC Used Aquifer Pennsylvania GW MSC Nonuse Aquifer PA Defaults Residential Volatilization to Indoor Air Screen* TRICHLOROPROPENE, 1,2, TRIMETHYLBENZENE, 1,3, (TRIMETHYLBENZENE, 1,2,4-) TRIMETHYLBENZENE, 1,3, VINYL ACETATE VINYL BROMIDE (BROMOETHENE) VINYL CHLORIDE XYLENES (TOTAL) * PA defaults using USEPA J&E GWSCREEN.XLS version /01; PA Soils parameters; 15 cm to bottom of enclosed space; 150 cm to water table; RL = 10-5 ; HQ =1 NOC - Not of concern, value above constituent water solubility NA - Not available Note: Bold face values indicate a COPIAC / DRAFT /Page 17

20 CAS Number Table 2 Groundwater Screening Values (µg/l) for Protection of Indoor Air: (Commercial/Industrial) Regulated Substance Pennsylvania GW MSC Used Aquifer Pennsylvania GW MSC Nonuse Aquifer USEPA-PA Defaults Volatilization to Indoor Air Screen 1 USEPA-PA Defaults PELs Volatilization to Indoor Air Screen ACENAPHTHENE NOC NOC ACENAPHTHYLENE NOC NOC ACETALDEHYDE NOC ACETONE NOC NOC ACETONITRILE NOC ACETOPHENONE NOC NOC ACROLEIN ACRYLAMIDE ACRYLIC ACID NOC ACRYLONITRILE NOC ALLYL ALCOHOL NOC ANILINE NOC ANTHRACENE NOC NOC BENZENE NOC BENZOTRICHLORIDE NOC BENZYL CHLORIDE NOC BIPHENYL, 1, NOC NOC BIS(2-CHLOROETHYL)ETHER NOC BIS(2-CHLORO NOC ISOPROPYL)ETHER BIS(CHLOROMETHYL)ETHER NOC BROMOCHLOROMETHANE NOC BROMODICHLOROMETHANE NOC BROMOMETHANE NOC BUTADIENE, 1, NOC BUTYL ALCOHOL, N NOC NOC BUTYLBENZENE, N NOC NOC BUTYLBENZENE, SEC NOC NOC BUTYLBENZENE, TERT NOC NOC CARBON DISULFIDE NOC CARBON TETRACHLORIDE NOC CHLORO-1,1-DIFLUOROETHANE, NOC NOC CHLORO-1-PROPENE, 3- (ALLYL CHLORIDE) CHLOROBENZENE NOC CHLOROBUTANE, NOC NOC CHLORODIBROMOMETHANE NOC CHLORODIFLUOROMETHANE NOC NOC CHLOROETHANE NOC CHLOROFORM NOC CHLORONAPHTHALENE, NOC NOC CHLOROPHENOL, NOC CHLOROPRENE NOC / DRAFT /Page 18

21 Table 2 Groundwater Screening Values (µg/l) for Protection of Indoor Air: (Commercial/Industrial) CAS Number Regulated Substance Pennsylvania GW MSC Used Aquifer Pennsylvania GW MSC Nonuse Aquifer USEPA-PA Defaults Volatilization to Indoor Air Screen 1 USEPA-PA Defaults PELs Volatilization to Indoor Air Screen CHLOROPROPANE, NOC CHLOROTOLUENE, O NOC CRESOL(S) NOC NOC CRESOL, O- (METHYLPHENOL, NOC NOC 2-) CROTONALDEHYDE NOC CROTONALDEHYDE, TRANS NOC CUMENE NOC NOC CYCLOHEXANONE NOC NOC DIBROMO-3-CHLOROPROPANE, , DIBROMOETHANE, 1, NOC (ETHYLENE DIBROMIDE) DIBROMOMETHANE NOC DICHLORO-2-BUTENE, 1, NOC DICHLOROBENZENE, 1, NOC NOC DICHLOROBENZENE, 1, NA NA DICHLOROBENZENE, 1, NOC DICHLORODIFLUOROMETHANE NOC (FREON 12) DICHLOROETHANE, 1, NOC DICHLOROETHANE, 1, NOC DICHLOROETHYLENE, 1, NOC DICHLOROETHYLENE, CIS-1, NOC DICHLOROETHYLENE, TRANS NOC 1, DICHLOROMETHANE NOC (METHYLENE CHLORIDE) DICHLOROPROPANE, 1, NOC DICHLOROPROPENE, 1, NOC DICHLOROPROPIONIC ACID, NOC NOC 2,2- (DALAPON) DICYCLOPENTADIENE NOC DIMETHYLANILINE, N,N NOC DIOXANE, 1, NOC EPICHLOROHYDRIN NOC ETHOXYETHANOL, 2- (EGEE) NOC NOC ETHYL ACETATE NOC NOC ETHYL ACRYLATE NOC ETHYL BENZENE NOC ETHYL NOC NOC DIPROPYLTHIOCARBAMATE, S- (EPTC) ETHYL ETHER NOC ETHYL METHACRYLATE NOC ETHYLENE GLYCOL NOC NOC / DRAFT /Page 19

22 Table 2 Groundwater Screening Values (µg/l) for Protection of Indoor Air: (Commercial/Industrial) CAS Number Regulated Substance Pennsylvania GW MSC Used Aquifer Pennsylvania GW MSC Nonuse Aquifer USEPA-PA Defaults Volatilization to Indoor Air Screen 1 USEPA-PA Defaults PELs Volatilization to Indoor Air Screen FLUORENE NOC NOC FLUOROTRICHLOROMETHANE NOC (FREON 11) FORMALDEHYDE NOC FORMIC ACID NOC NOC FURAN NOC FURFURAL NOC HEXANE NOC NOC HYDRAZINE/HYDRAZINE NOC SULFATE ISOBUTYL ALCOHOL NOC NOC METHACRYLONITRILE NOC METHANOL NOC NOC METHOXYETHANOL, NOC METHYL ACETATE NOC METHYL ACRYLATE NOC METHYL CHLORIDE NOC METHYL ETHYL KETONE NOC METHYL ISOBUTYL KETONE NOC METHYL METHACRYLATE NOC METHYL STYRENE (MIXED NOC 4 ISOMERS) METHYL TERT-BUTYL ETHER NOC (MTBE) METHYLNAPHTHALENE, NOC NOC METHYLSTYRENE, ALPHA NOC NAPHTHALENE NOC NOC NITROBENZENE NOC NITROPHENOL, NOC NOC NITROPROPANE, NOC NITROSODIETHYLAMINE, N NOC NITROSODIMETHYLAMINE, N NOC NITROSO-DI-N-BUTYLAMINE, N NOC PCB-1221 (AROCLOR) NA NA PHENANTHRENE NOC NOC PHENOL NOC NOC PROPYLBENZENE, N NOC NOC PROPYLENE OXIDE NOC PYRIDINE NOC STYRENE NOC NOC TETRACHLOROETHANE, 1,1,1, NOC TETRACHLOROETHANE, 1,1,2, NOC TETRACHLOROETHYLENE (PCE) NOC TOLUENE NOC NOC TRIBROMOMETHANE NOC / DRAFT /Page 20

23 CAS Number Table 2 Groundwater Screening Values (µg/l) for Protection of Indoor Air: (Commercial/Industrial) Regulated Substance (BROMOFORM) TRICHLORO-1,2,2- Pennsylvania GW MSC Used Aquifer Pennsylvania GW MSC Nonuse Aquifer USEPA-PA Defaults Volatilization to Indoor Air Screen 1 USEPA-PA Defaults PELs Volatilization to Indoor Air Screen NOC NOC TRIFLUOROETHANE, 1,1, TRICHLOROBENZENE, 1,2, NOC NOC TRICHLOROBENZENE, 1,3, NOC NOC TRICHLOROETHANE, 1,1, NOC NOC TRICHLOROETHANE, 1,1, NOC TRICHLOROETHYLENE (TCE) NOC TRICHLOROPROPANE, 1,1, NOC TRICHLOROPROPANE, 1,2, NOC TRICHLOROPROPENE, 1,2, NOC TRIMETHYLBENZENE, 1,3, NOC (TRIMETHYLBENZENE, 1,2,4-) TRIMETHYLBENZENE, 1,3, NOC VINYL ACETATE NOC VINYL BROMIDE NOC (BROMOETHENE) VINYL CHLORIDE XYLENES (TOTAL) NOC NOC 1 PA defaults using USEPA J&E Version 2.3; 03/01, receptor, RL = 10-5, HQ = 1 2 PA defaults using USEPA J&E Version 2.3; 03/01, receptor; Use this OSHA-derived Screen when OSHA regulations are fully implemented and documented inside a workplace building. NA - Not available NOC - Not of concern, value above constituent water solubility Note: Bold face values indicate a COPIAC / DRAFT /Page 21

24 CAS Number Regulated Substance Table 3 Indoor Air Criteria and Odor Thresholds Residential MSC (mg/m 3 ) MSC (mg/m 3 ) EPA Region III RBC (mg/m 3 )* ACGIH TLV (mg/m 3 ) OSHA PEL (mg/m 3 ) Odor Threshold (mg/m 3 ) ACENAPHTHENE ACENAPHTHYLENE ACETALDEHYDE ACETONE ACETONITRILE ACETOPHENONE ACROLEIN ACRYLAMIDE ACRYLIC ACID ACRYLONITRILE ALLYL ALCOHOL ANILINE ANTHRACENE BENZENE (1) BENZOTRICHLORIDE BENZYL CHLORIDE BIPHENYL, 1, BIS(2-CHLOROETHYL)ETHER ceiling 90 limit: BIS(2-CHLORO-ISOPROPYL)ETHER BIS(CHLOROMETHYL)ETHER BROMOCHLOROMETHANE BROMODICHLOROMETHANE BROMOMETHANE ceiling 80 limit: BUTADIENE, 1, BUTYL ALCOHOL, N BUTYLBENZENE, N BUTYLBENZENE, SEC BUTYLBENZENE, TERT CARBON DISULFIDE CARBON TETRACHLORIDE (1) CHLORO-1,1-DIFLUOROETHANE, CHLORO-1-PROPENE, 3- (ALLYL CHLORIDE) / DRAFT /Page 22