UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, D.C. 20460 *«. OFFICE OF SOLID WASTE AND EMERGENCY RESPONSE OCT251993 OSWER Directive 9360.1-02 MEMORANDUM SUBJECT: Final Guidance on Numeric Removal Action Levels for Contaminated Drinking Water Sites FROM: Deborah Y. Dietrich, Director /S/ Emergency Response Division TO: Removal Managers Regions I - X Purpose The purpose of this memorandum is to transmit the final OERR methodology and guidance on the calculation of numeric removal action levels (RALs), to assist Superfund personnel in deciding whether to provide alternate sources of drinking water to populations adversely affected by releases of hazardous substances into the environment. Introduction RALs are drinking water concentrations of contaminants that are considered, along with other factors, in determining whether to provide alternate water supplies under Superfund removal authority. RALs were established in OSWER (Office of Solid Waste and Emergency Response) Directive 9360.1-01, Interim Final Guidance on Removal Action Levels at Contaminated Drinking Water Sites (October 1987). That directive defined two types of RALs: (1) numeric levels for individual substances, which apply generally across most sites, and (2) site-specific levels, which are based on a more detailed analysis of conditions at a particular site and are determined on a case-by-case basis. A methodology for calculating numeric RALs for drinking water was presented in the 1987 OSWER directive, and values for 34 substances were listed in Exhibit 2 of that directive. The Office of Emergency and Remedial Response (OERR)/Emergency Response Division (ERD) distributed an updated and significantly expanded table of numeric RALs in April 1991 that listed values - calculated using the same methodology described in the 1987 OSWER Directive - for 165 substances. Word-Searchable Version - Not a true copy ------- -2- Objective ERD has adopted a new methodology for determining RALs for contaminated drinking water. This memorandum explains the new methodology and provides the rationale for adopting it. As discussed in the next section, the new methodology better matches the needs of the Superfund removal program and is more consistent with procedures used by the Office of Water (OW) than the previous guidance. The attached table lists updated numeric RALs for 204 substances developed using the new methodology. These updated RALs supersede the values given in the April 1991 table distributed by ERD. Regions should begin using the newly updated RALs immediately, in the same manner as previous values were used (i.e., as one factor in deciding whether to provide alternate water supplies under Superfund removal authority). Issuance of this update of numeric RALs does not in any way restrict the existing flexibility of a Regional office to develop and apply site-specific RALs. Note that the updated numeric RALs apply to new removal starts, and, in general, are not intended to affect ongoing or completed removal actions. Implementation New RAL Methodology: Background and Rationale ERD has adopted the procedures recently developed by OW for determining short-term acceptable risk (STAR) levels as the new methodology for setting numeric RALs for drinking water. The STAR is one factor, along with cost and affordability considerations, used in making unreasonable risk to health (URTH) determinations under the Safe Drinking Water Act. Under the Act, EPA (or primacy states) may grant a public water system a variance or exemption from a Maximum Contaminant Level (MCL; for definition, see box on page 5) if it finds that the variance or exemption will not result in an URTH. The STAR is defined as the upper-bound concentration of a contaminant in drinking water, generally above the MCL (and never lower than the MCL), that would not pose a health risk for exposures lasting up to seven years (approximately 10 percent of an individual's lifetime). As of the date of this memorandum, OW has released STAR values for 47 chemical substances, all of which are included in the attached table of updated RALs. In addition, OW has issued Guidance for Determining Unreasonable Risks to Health (EPA/OW/Office of Science and Technology, 1992), which describes in detail the procedures for determining STARS. The guidance also allows for development of site-specific URTHs, where appropriate, and lists factors to be considered in their development. Word-Searchable Version - Not a true copy ------- -3- ERD adopted the STAR methodology to replace its previous approach to determining RALs for drinking water primarily for the following reasons: • As risk-based levels developed specifically for relatively short-term exposures to individual contaminants in drinking water, STARs are the Agency numbers that most closely correspond to the needs of the Superfund removal program for action levels. Levels based on exposure periods of up to seven years are more relevant to removal program decision-making than levels based on lifetime exposures (as used in the previous approach). It is important to note, however, that while the STAR is a level for short-term exposure, it is derived from numbers (e.g., MCLs and drinking water equivalent levels (DWELs)) that are protective over a lifetime of exposure. • STARs are developed using OW procedures and data, which are extensively reviewed both within the Agency and by independent scientific groups, including EPA's Science Advisory Board and the National Academy of Sciences. In addition, the STAR methodology was subject to public review and comment as part of its development process. • Problems that potentially could arise from inconsistencies between RALs and STARs will be avoided, as EPA will be using the same approach to evaluating short-term exposures to drinking water contamination in the Superfund removal program as in the OW drinking water program. Thus, the new methodology enhances both the scientific credibility of RALs and their consistency with OW procedures and data. Differences Between the Old and New Methodologies There are several differences between the newly adopted methodology and the previous approach to determining RALs, including: (1) primary reliance on OW data and procedures; (2) explicit consideration of short-term toxicity data; (3) elimination of the possibility of a numeric RAL being lower than the corresponding MCL; and (4) elimination of the two-fold reduction factor applied to volatile non-carcinogens. The previously used adjustment factor for volatiles was eliminated because the OW values and calculation procedures that are the basis of the new methodology are considered protective of exposures from inhalation of volatiles released from drinking water as well as from direct ingestion. It is important to note that exposure to volatiles other than through ingestion is receiving much Agency attention. The Word-Searchable Version - Not a true copy ------- -4- Office of Water is investigating methodologies for assessing inhalation risks from volatile contaminants (mainly trihalomethanes) and is scheduled to take action on this issue this year. What the Office of Water does with trihalomethanes will have important implications for other volatiles and may lead to some modifications of the assumptions and methodologies used to derive STAR levels and other drinking water standards. Currently, the Office of Water considers the RfD/DWEL, longer-term health advisory, and cancer risk level protective for volatile and non-volatile contaminants because exposure from sources other than drinking water are not factored out of the risk calculations as they are for the MCL/MCLG. This approach continues to have the approval of the NAS and SAB. Please keep in mind that regional personnel may always choose to factor in inhalation exposure as they would any other site-specific consideration when deciding to perform a removal action. In addition, OW's 10-day Health Advisory values are no longer considered in the RAL process. Although never part of the actual calculation procedure for numeric RALs, 10-day Health Advisories were listed in the October 1987 and April 1991 tables of values, and the October 1987 directive instructed that they be considered in certain "special cases" (including the case referred to above, which no longer occurs, when a calculated numeric RAL was lower than the corresponding MCL). Because 10-day Health Advisories are developed for much shorter exposure periods (i.e., 10 days) than is appropriate for many removal site situations, where exposure to contaminated drinking water may have occurred over weeks, months, or even years, they are not considered adequately protective, in general, for application at removal sites. Moveover, at many cites there is substantial uncertainty over exactly how long exposures have been occurring. Therefore, the newly updated RALs, which are based on a more relevant exposure period, should be used rather than 10-day Health Advisories, except possibly in the (presumably rare) situation where it can be documented that exposure is extremely short-term and will not exceed approximately 10 days in duration. Overview of OW s STAR Methodology Several toxicity- or risk-based levels developed by OW are considered in developing STARs. These levels are defined in the box on the next page. The STAR methodology is described in detail in OW's referenced 1992 URTH guidance. Word-Searchable Version - Not a true copy ------- -5- MCLG (maximum contaminant level goal): A non-regulatory health goal based solely on considerations of protecting the public from adverse health effects of drinking water contamination. MCL (maximum contaminant level): A regulatory level that sets the maximum permissible concentration of a contaminant in water delivered to users of public water systems. The MCL is set as close to the MCLG as feasible, considering such factors as analytical capability, treatment availability, and treatment costs. DWEL (drinking water equivalent level): The concentration of a contaminant in drinking water that is not expected to cause any adverse non-cancer health effects in humans over a lifetime of continuous exposure. The DWEL, in mg/1, is calculated by multiplying the oral reference dose (RfD), in mg/kg-day, by 70 kg (standard adult body weight) and dividing it by 2 liters/day (standard adult water consumption rate). Longer-term HA (health advisory) (child): The concentration of a contaminant in drinking water that is not expected to cause any adverse non-cancer health effects in children over a continuous exposure period of up to seven years. The Longer-term HA is calculated similarly to the DWEL, but instead of the RfD, a no- or lowest-observed- adverse-effect-level (NOAEL or LOAEL) from a study in which the exposure duration is comparable to seven years of human exposure is used. The NOAEL or LOAEL, in mg/kg-day, is divided by appropriate uncertainty factors, then multiplied by 10 kg (standard child body weight) and divided by 1 I/day (standard child water consumption rate). 10~4 cancer risk level: The concentration of a contaminant in drinking water that would result in a 10~4 upper-bound lifetime excess cancer risk to an individual exposed continuously over a lifetime (other pre-specifled risks, such as 10~5, also can be defined) . The cancer risk level is calculated based on the pre-specifled risk, the contaminant's cancer slope factor, the standard adult body weight of 70 kg, and the standard adult water consumption rate of 2 I/day. The level that ultimately becomes the basis, for a STAR depends in part on the type of effects caused by the substance. Of particular importance in the STAR methodology is a substance's potential for human carcinogenicity, as reflected in EPA's cancer weight-of-evidence classification. EPA's classification system Word-Searchable Version - Not a true copy ------- (described in detail in Guidelines for Carcinogen Risk Assessment, 51 Federal Register 33992, September 24, 1986) defines the following major categories: A Human carcinogen B Probable human carcinogen C Possible human carcinogen D Not classifiable as to human carcinogenicity E Evidence of non-carcinogenicity For Group A or B carcinogens, the STAR is set at the MCL whenever the MCL is greater than or equal to the 10~4 cancer risk level. When the MCL is less than the 10~4 cancer risk level, the STAR is the lowest value among the 10~4 cancer risk level, the DWEL, or the Longer-term HA (child). As examples of these two cases, consider ethylene dibromide and benzene. The STAR for ethylene dibromide is set at the MCL, 0.05 jUg/1, because the MCL is greater than the 10~4 cancer risk level, 0.04 /ug/1. • Conversely, the STAR for benzene is set at the 10~4 cancer risk level, 100 jjg/1, because the MCL of 5 /ug/1 is less than the 10~4 cancer risk level (no DWEL or Longer-term HA (child) available). For Group D, E, or unrated substances (i.e., substances considered to be non-carcinogens for purposes of this methodology), the STAR is set at the MCL whenever a contaminant's, main health effects are very short-term and the MCL is based on effects of acute exposures. Otherwise, the STAR is the lower of the DWEL or Longer-term HA (child) values. For example, the DWEL for methoxychlor is 200 //g/1, the Longer-term HA (child) is 50 //g/1, and the MCL is not based on very short-term effects. Therefore, the STAR is set at 50 //g/1. For Group C carcinogens, which have limited evidence for human carcinogenicity, the STAR is usually based on non-cancer effects and is the lowest value among the DWEL, the Longer-term HA (child), or the MCLG multiplied by 10.l The 10-fold adjustment of the MCLG removes the additional safety factor included in the MCLG for Group C carcinogens to protect against possible cancers resulting from lifetime exposure, a factor not considered necessary for developing a STAR. As an example, consider atrazine, which has a DWEL of 200 //g/1, a Longer-term HA (child) of 60 //g/1, and an "MCLG times 10" value of 30 //g/1 (MCLG equals 3 //g/1) . Therefore, the STAR is set at the lowest of these three values, or 30 //g/1. 1 If toxicity information is inadequate to develop a DWEL or Longer-term HA (child), the MCLG (and therefore the STAR) can be based on a cancer risk level. Word-Searchable Version - Not a true copy ------- -7- Development of Numeric RALs Using the STAR Methodology If a STAR value is available from OW, it is used without adjustment as the numeric RAL. If OW has evaluated a substance but has not developed a STAR, the numeric RAL is determined using the STAR methodology and input data from OW. When an OW evaluation is unavailable for a substance, a few modifications to the STAR methodology are necessary because some of the needed input values may not be available. For substances lacking an OW evaluation, RALs are based on a subset of the STAR procedures. MCLs, MCLGs, and Longer-term HAs (child) are unavailable in these situations and are not considered; DWELs and cancer risk levels are calculated based on toxicity information (oral RfDs, oral cancer weight-of-evidence ratings, and oral cancer slope factors) from other Agency data sources and then used to determine the RAL. EPA's on-line Integrated Risk Information System (IRIS) should be the first source consulted for this toxicity information (assuming no information is available directly from OW), followed by EPA's Health Effects Assessment Summary Tables (HEAST) (Office of Research and Development, March 1992 or most recent update). Exhibit 1 is a matrix summarizing the new numeric RAL methodology for both situations - when an OW evaluation is available for a substance and when an OW evaluation is unavailable. Exhibits 2A (OW evaluation available) and 2B (OW evaluation unavailable) are a parallel set of flowcharts depicting the RAL determination process. Site-specific RALs A significant health threat may exist at a site even if no substance is currently present in drinking water at a concentration exceeding its numeric RAL. A removal action may be initiated if the health risk at a site has been analyzed in detail and the analysis indicates that a serious risk is present due to site-specific factors. Examples of such factors include evidence that a ground-water plume with contamination exceeding a RAL is moving toward drinking water wells, current contaminant levels will likely increase (e.g., due to increased pumping from an aquifer anticipated during summer months), people have been drinking contaminated water for a long period of time already, multiple contaminants are likely to result in additive or synergistic effects, or sensitive populations are present and being exposed to the contamination. OW's URTH guidance, adopted as the new basis for numeric RALs, provides for similar site-specific flexibility to depart from recommended STAR levels based on considerations such as site-specific exposures, exposures from other sources, past exposure (if known), exposure to mixtures of drinking water contaminants, population sensitivity, chemical characteristics such as volatility, or other factors not directly related to the contaminant. Word-Searchable Version - Not a true copy ------- Decisions to undertake a removal action when a numeric RAL has not been exceeded should be made on a case-by-case basis. Because ERD wishes to know how guidance is used in the Regions, please notify your Regional Coordinator of any Action Memo approved for contaminated drinking water sites where the removal action decision is based solely on site-specific factors (i.e., no numeric RAL is exceeded). Information Sources The attached table of numeric RALs for drinking water, dated November 1992, lists values for many substances of concern at drinking water contamination sites. ERD plans to distribute updates to the table, as appropriate, such as when OW releases a significant number of new or revised STARs. In the meantime, Regional offices should use the most up-to-date STAR available for a substance as the numeric RAL. If OW has released a revised STAR that differs from the value given in the attached table, Regional offices should use that revised STAR as the numeric RAL. Information on STARs and other OW data used in the new RAL methodology is available through the Safe Drinking Water Hotline at 800-426-4791. If a substance of concern is not listed in the attached table, Regional offices may determine the appropriate numeric RAL by applying the methodology summarized in this memorandum (refer to the OW URTH guidance for a more detailed description of the STAR procedures). Alternatively, a Regional office may request ERD's assistance in determining the appropriate numeric RAL. If a Region decides to develop a numeric RAL itself, it must first check with OW to determine if a STAR is available and, if not, whether OW has developed any of the other risk-based levels needed as inputs (e.g., MCL/MCLG, DWEL, Longer-term HA (child), 10~4 cancer risk level). If there is no information available from OW, the Regional office may calculate and use DWELs and cancer risk levels to develop numeric RALs, based on toxicity information in IRIS or HEAST. For additional information on IRIS, contact user support in the Office of Research and Development, Cincinnati, OH, at 513-569-7254. For additional information on HEAST, contact the Superfund Health Risk Technical Support Center in the Office of Research and Development, Cincinnati, OH, at 513-569-7300. Word-Searchable Version - Not a true copy ------- -9- Substances With Significant Changes in Numeric RALs Exhibit 3 lists those substances for which the RAL has changed significantly (defined as more than a factor of two) from the value in the table distributed by ERD in April 1991. Please distribute this update to all removal program staff in your Regional office. If you have any questions on this document, contact Lisa Boynton (OERR/ERD), at 703-603-9052. Word-Searchable Version - Not a true copy ------- -10- EXHIBIT 1 SUMMARY OF NEW METHODOLOGY FOR NUMERIC RALs Cancer Weight- of-evidence Class OW Evaluation of Substance Available1 OW Evaluation of Substance Unavailable2 A or B ! If MCL > ICr4 cancer risk level: RAL = MCL ! If MCL < ICr4 cancer risk level: RAL = lowest of: 1CT4 cancer risk level, or DWEL, or Longer-term HA (child) ! RAL = lower of: 1CT4 cancer risk level, or DWEL ! RAL = lowest of: MCLG x 10, or DWEL, or Longer-term HA (child) ! If DWEL can be calculated: RAL = DWEL x 0.2 (20% relative source contribution assumed) ! If DWEL cannot be calculated: RAL = 10~4 cancer risk level D, E, or unrated ! If MCL based on acute toxicity: RAL = MCL ! If MCL not based on acute toxicity: RAL = lower of: DWEL, or Longer-term HA (child) ! RAL = DWEL 1 Use OW values for MCL, MCLG, DWEL, Longer-term HA (child), and 10~4 cancer risk level. 2 Obtain oral RfD, oral cancer weight-of-evidence rating, and oral cancer slope factor from IRIS (or HEAST if unavailable in IRIS), then calculate DWEL and 10~4 cancer risk level. Word-Searchable Version - Not a true copy ------- EXHIBIT 2A DECISION FLOW DIAGRAM FOR RAL METHODOLOGY: OFFICE OF WATER EVALUATION AVAILABLE no RAL = MCL RAL = lowest of: 10-4 cancer risk level, or DWEL, or Longer-term HA RAL = lowest of: MCLGxlO, or DWEL, or Longer-term HA (child) RAL * lower of: DWEL, or Longer-term HA (child) Word-Searchable Version - Not a true copy ------- EXHIBIT 2B DECISION FLOW DIAGRAM FOR RAL METHODOLOGY: OFFICE OF WATER EVALUATION NOT AVAILABLE START yes no yes no RAL = lower of: 10-4 cancer risk level, orDWEL RAL = DWEL x 0.2 if DWEL is unavailable: RAL = 10-4 cancer risk level RAL= DWEL Word-Searchable Version - Not a true copy ------- -13- EXHIBIT 3 SUBSTANCES FOR WHICH NUMERIC RALs HAVE CHANGED SIGNIFICANTLY Substance 1991 (Old) RAL (pg/D New RAL (pg/D Factor Increase/ Decrease1 ORGANICS Acifluorfen (Tackle) Acrylonitrile Aldicarb (Temik) Atrazine Baygon Bromodichlorome thane Bromome thane Carbaryl Carbof uran Carbon tetrachloride Carboxin Chloramben Chlorodibromome thane Chlorome thane Chlorophenol (2-) Chlorothalonil Chlorotoluene (0-) Chlorpyrif os Cyanazine 2,4-D (2, 4-Dichloro- phenoxyacetic acid) Dacthal (DCPA) Dalapon Diazinon Dicamba Dichlorobenzene (1,4-) Dichloroethylene (1,1-) Dichlorophenol (2,4-) Dimethyl phthalate Dinoseb 460 6.5 2.5 180 140 27 25 3,500 180 12 3,500 530 42 270 180 530 350 110 70 350 18,000 1,100 32 46 150 5.8 110 35,000 35 100 1 7 30 40 60 50 1,000 50 30 1,000 200 700 100 50 150 700 30 20 100 5,000 300 3 300 750 70 30 350,000 10 -4.6 -6.5 + 2.8 -6.0 -3.5 + 2.2 + 2.0 -3.5 -3.6 + 2.5 -3.5 -2.7 + 17 -2.7 -3.6 -3.5 + 2.0 -3.7 -3.5 -3.5 -3.6 -3.6 -11 + 6.5 + 5.0 + 12 -3.7 + 10 -3.5 Word-Searchable Version - Not a true copy ------- -14- EXHIBIT 3 (continued) SUBSTANCES FOR WHICH NUMERIC RALs HAVE CHANGED SIGNIFICANTLY Substance Dioxane (1,4-) Diphenamid Endothall Endrin Ethylene glycol Fonof os Glyphosate Hexane (n-) Isophorone Isopropylbenzene (Cumene) Malathion Maleic hydrazide MCPA ( (4-Chloro-2- methylphenoxy) -acetic acid) Methomyl Methoxychlor Metolachlor Metribuzin Oxamyl (Vydate) Paraquat Pentachloronitrobenzene Phenol Picloram Prometon Pronamide (Kerb) Propachlor RDX (Hexahydro-1 , 3 , 5- trinitro- 1,3, 5-triazine Styrene TCDD (2,3,7,8-) (Dioxin) Tebuthiuron Terbuf os 1991 (Old) RAL (ug/1) 320 1, 100 700 11 70,000 70 3,500 21,000 850 1,400 700 18,000 18 880 180 5,300 880 880 160 14 21,000 2,500 530 2, 600 460 32 3,500 22 pcg/1 2,500 3.5 New RAL (ug/1) 700 300 200 3 6,000 20 1,000 4,000 7,000 14,000 200 5,000 50 300 50 2,000 300 200 50 100 6,000 700 200 800 100 100 1,000 50 pcg/1 700 1 Factor Increase/ Decrease1 + 2.2 -3.7 -3.5 -3.7 12 -3.5 -3.5 -5.3 + 8.3 + 10 -3.5 -3.6 + 2.8 -2.9 -3.6 -2.7 -2.9 -4.4 -3.2 + 7.2 -3.5 -3.6 -2.7 -3.3 -4.6 + 3.2 -3.5 + 2.3 -3.6 -3.5 Word-Searchable Version - Not a true copy ------- -15- EXHIBIT 3 (continued) SUBSTANCES FOR WHICH NUMERIC RALs HAVE CHANGED SIGNIFICANTLY Substance Tetrachloroethane (1,1,1,2-) Tetrachloroethane (1,1,2,2-) 2,4,5-TP (2(2,4,5- Trichlorophenoxy) propionic acid) Trichlorobenzene (1,2,4- ) Trichloroethene (1,1,2-) Trif luralin 1991 (Old) RAL (ug/1) 130 18 280 46 61 260 New RAL (ug/1) 900 2 70 100 30 80 Factor Increase/ Decrease1 + 6.9 -9.0 -4.0 + 2.2 -2.1 -3.3 INORGANICS Arsenic Barium Boron Cadmium Cyanide Flouride Maganese Molybdenum Nitrite Vanadium Zinc 2 1,800 3,200 18 700 2,100 3,500 140 3,500 250 7,000 50 5,000 900 5 200 5,000 200 10 1,000 30 3,000 + 25 + 2.8 -3.6 -3.6 -3.5 + 2.4 -17 -14 -3.5 -8.3 -2.3 1 The ratio between the new RAL and the old RAL. A "+" indicates that the RAL has increased, while a "-" indicates that the RAL has decreased. Word-Searchable Version - Not a true copy ------- NUMERIC REMOVAL ACTION LEVELS FOR CONTAMINATED DRINKING WATER SITES Tables Emergency Response Division Office of Solid Waste and Emergency Response U.S. Environmental Protection Agency Washington, DC 20460 May 1993 Word-Searchable Version - Not a true copy ------- CAS# DWEL Table Acronyms Chemical Abstract Number Drinking Water Equivalent Level (calculated by multiplying the oral RfD by 70 kilograms (adult body weight) and dividing by the average volume of water (2 liters) consumed per day) Longer-term HA (Child) Drinking Water Health Advisory for 10 kg child consuming 1 liter per day for up to 7 years MCL MCLG MFL Treat. Tech. URTH-STAR Maximum Contaminant Level (National Primary Drinking Water Standard) Maximum Contaminant Level Goal Million Fibers per Liter MCL is based on the capability of the treatment technology Draft Short-term Risk Level (STAR) recommended for an Unreasonable Risk to Health (URTH) under Safe Drinking Water Act Word-Searchable Version - Not a true copy ------- NUMERIC REMOVAL ACTION LEVELS FOR CONTAMINATED DRINKING WATER SITES PRIMARY DRINKING WATER STANDARDS AND HEALTH ADVISORIES May 1993 Chemical Cancer Risk INORGANICS CAS # 10 4 Cancer Cancer Group Risk (Mg/L) Ammonia 7664417 D — Antimony 7440360 D — Arsenic 7440382 A 2 Asbestos >10 |im 1332214 A 700 MFL Barium 7440393 D — Beryllium 7440417 B2 0.8 Boron 7440428 D — Cadmium 7440439 D — Chloramines 10599903 Da — Chlorine 7782505 D — Chlorine dioxide 10049044 D — Chromium III (see Chromium total) 16065831 Chromium VI (see Chromium total) 1 8540299 Chromium (total) — D — Copper 7440508 D — Cyanide 57125 D — Flouride 16984488 — — Hypochlorite 7681529 — — Hypochlorous acid 7790923 — — Lead at tap 7439921 B2 — Manganese 7439965 Da — Mercury 7439976 D — Molybdenum 7439987 D — Nickel 7440020 D — Nitrate 14797558 D — Nitrite 14797650 — — Nitrate+Nitrite — — — Standards and Health Advisories Longer- DWEL term HA MCL/MCLG (Child) (Hg/L) (ng/L) (ng/L) — — — 15 15 6/6 — — 50 7— — — 7 MFL / 7 MFL 2,000 — 2,000 / 2,000 200 4,000 4 / 4 3,000 900 — 20 5 5/5 3,300 1,000 — / 4,000 — — — / 4,000 100 — — 780 200 200 100/100 — — Treat. T. 7 1,300 800 200 200 / 200 — — 4,000 / 4,000 — — — / 4,000 — — — / 4,000 — — Treat. Tech. / 0 200 — — /200 10 — 2/2 200 10 — 600 500 100/100 56,000 — 10,000/10,000 — — 1,000/1,000 — — 10,000/10,000 URTH -STAR- Level (Mg/L) — — — 70 MFL — — — 5 — — — 200 1,300 — 5,000C — — 30C — 10 — — 10,000 1,000 10,000 Superfund Removal Action Level (Mg/L) 34,000' (taste) 15 50 70 MFL" 2,000 1 900 5 1,000 — 100 200 1,300 200 5,000 — — 30 200 10 10 500 10,000 1,000 10,000 Word-Searchable Version - Not a true copy ------- NUMERIC REMOVAL ACTION LEVELS FOR CONTAMINATED DRINKING WATER SITES PRIMARY DRINKING WATER STANDARDS AND HEALTH ADVISORIES May 1993 Chemical IN ORGANICS CAS # Selenium 7782492 Silver 7440224 Strontium 7440246 Sulfate 7757826 Thallium 7440280 Vanadium 7440622 White phosphorus 772314 Zinc 7440666 Zinc chloride (measured as zinc) — Cancer Risk 104 Cancer Cancer Group Risk (Mg/L) — — D — D — — — — — D — D — D — D — Standards and Health Advisories Longer- DWEL term HA MCL/MCLG (Child) (Mg/L) (Mg/L) (Mg/L) 200 — 50/50 200 200 — 90,000 25,000 — — — — 2 7 2/0.5 250s — — 0.5 — — 11,000 3,000 — 11,000 3,000 — Superfund URTH Removal -STAR- Action Level Level 200 200 — 100d — 25,000 — 250,000 (aesthetics) — 2 — 250 — 0.5 — 3,000 — 3,000 aBased on data from IRIS or HEAST in the absence of a published U.S. EPA, Office of Water value b MFL = million fibers per liter c Based on special considerations d Secondary Maximum Contaminant Level intended to protect general public from argyuria (a cosmetic affect) over a lifetime Word-Searchable Version - Not a true copy ------- NUMERIC REMOVAL ACTION LEVELS FOR CONTAMINATED DRINKING WATER SITES PRIMARY DRINKING WATER STANDARDS AND HEALTH ADVISORIES May 1993 Chemical ORGANICS CAS # Acenaphthene 83329 Acetone 67641 Acifluoren (Tackle) 62476599 Acrylamide (2-Propenamide) 79061 Acrylonitrile 107131 Adipates (Diethylhexyl) 103231 Alachlor 15972608 Aldicarb (Temik) 1 16063 Aldicarb sulfone 1646884 Aldicarb suffoxide — Aldrin 309002 Ametyrn 834128 Ammonium sulfamate 7773060 Anthracene 120127 Atrazine 1912249 Baygon 114261 Bentazon 25057890 Benz(a)anthracene 56553 Benzene 71432 Benzo(a)pyrene 50328 Benzo(b)fluoranthene 205992 Benzo(k)fluoranthene 207089 bis-2-Chloroisopropyl ether 108601 Bromacil 314409 Bromochloromethane 74975 Bromodichloromethane 75274 Bromoform 75252 Cancer Risk 104 Cancer Cancer Group Risk (Mg/L) — — D — B2 100 B2 1 Bl 6 C — B2 40 D — D — D — B2 0.2 D — D — D — C — C — D — B2 — A 100 B2 — B2 — B2 — D — C — Ds — B2 60 B2 400 Standards and Health Advisories Longer- DWEL term HA (Child) (ug/L) (ug/L) 2,100 — 3,500a — 400 100 7 20 — — 20,000 — 400 — 35 — 35 — 35 — 1 0.3 300 900 8,000 20,000 11,000 — 200 60 100 40 90 300 — — TJR] MCL/MCLG -ST.4 Le\ (^g/L) (MS/ — — — — — /o — Treat.Tech. / 0 1 — /O — 500 / 500 — Superfund [H Removal LR- Action rel Level L) (ug/L) 2,100 3,500 100 1 6 5,000 2/0 40 40 3/1 — 2/1 — 4/1 — — — — — — — — — 35 35 35 0.2 300 8,000 11,000 3/3 30 30 — — — 720 — 0.1/0 — 40 90 0.1 — — 5/0 100 100 — — — — — — 1,000 4,000 5,000 3,000 500 1,000 700 4,000 700 2,000 0.2/0 — 0.2/0 — 0.2/0 — — — — — — — 100/0 — 100/0 — 0.2 0.2 0.2 1,000 3,000 500 60 400 Word-Searchable Version - Not a true copy ------- NUMERIC REMOVAL ACTION LEVELS FOR CONTAMINATED DRINKING WATER SITES PRIMARY DRINKING WATER STANDARDS AND HEALTH ADVISORIES May 1993 Chemical ORGANICS CAS # Bromomethane (Methyl bromide) 74839 Butanone (2-) (see Methyl ethyl ketone) Butyl benzyl phthalate 85687 Butylate 2008415 Carbaryl 63252 Carbofuran 1563662 Carbon tetrachloride 56235 Carboxin 5234684 Chloral hydrate (Tnchloroacetaldehyde 302170 monohydrate) Chloramben 133904 Chlordane 57749 Chlorobenzene (see Monochlorobenzene) Chlorodibromomethane (Dibromochioro- 124481 methane) Chloroform (Tnchlorom ethane) 67663 Chloromethane (Methyl chloride) 74873 Chlorophenol (2-) 95578 Chloroyhalonil 1897456 Chlorotoluene, o- 95498 Chlorotoluene, p- 106434 Chlorpyrifos 2921882 Chrysene 218019 Cumene (see Isopropylbenzene) Cyanazine 21725462 2,4-D (2,4-Dichlorophenoxyacetic) 94757 Dacthal (DCPA) 1861321 Dalapon 75990 Cancer Risk 104 Cancer Cancer Group Risk (Mg/L) D — C — D — D — E — B2 30 D — C — D — B2 3 C — B2 600 C — D — B2 150 D — D — D — B2 — C — D — D D — Standards and Health Advisories Longer- DWEL term HA MCL/MCLG (Child) 40 100 — 6,000 — 100/0 2,000 1,000 — 4,000 1,000 — 200 50 40 / 40 30 70 5/0 4,000 1,000 — 70 200 — 760 500 200 — 2 — 2/0 700 2,000 100/0 400 100 100/0 100 400 — 200 50 — 500 200 — 700 2,000 — 700 2,000 — 100 30 — — — 0.2/0 70 20 —11 400 100 70 / 70 20,000 5,000 — 900 300 200 / 200 Superfund URTH Removal -STAR- Action Level Level (Mg/L) (Mg/L) — 40 — 6,000 — 1,000 — 1,000 50 50 30 30 — 1,000 — 70 — 200 2 2 — 700 — 100 — 100 — 50 — 150 — 700 — 700 — 30 — 0.2 — 20 100 100 — 5,000 — 300 Word-Searchable Version - Not a true copy ------- NUMERIC REMOVAL ACTION LEVELS FOR CONTAMINATED DRINKING WATER SITES PRIMARY DRINKING WATER STANDARDS AND HEALTH ADVISORIES May 1993 Chemical ORGANICS CAS # Di[2-ethylexyl]adipate 103231 Diazinon 333415 Dibenzo[a,h] anthracene 53703 Dibromoacetonitrile 3252435 Dibromochloromethane (see Chlorodibromomethane) Dibromochloropropane (DBCP) 96128 Dibromomethane (Methylene Bromide) 74953 Dibutyl phthalate (Di-n-butyl phthalate) 84742 Dicamba 1918009 Dichloroacetic acid 79436 Dichloroacetonitrile 3018120 Dichlorobenzene-o(l,2-) 95501 Dichlorobenzene -m ( 1 ,3-) 54 1 73 1 Dichlorobenzene -p ( 1 ,4-) 1 06467 Dichlorodifluoromethane (Freon-12) 75718 Dichloroethane(U-) 75343 Dichloroethane ( 1 ,2-) (Ethyiene 1 07062 dichloride) Dichloroethylene(l,l-) 75354 Dichloroethlene (cis- 1,2-) 156592 Dichloroethylene (trans- 1,2-) 156605 Dichloromethane (Methylene chloride) 75092 Dichlorophenol (2,4-) 120832 Dichloropropane(l,2-) 78875 Dichloropropene ( 1 ,3-) (cis and trans) 542756 Dieldrin 60571 Diethyl phthalate 84662 Diethylhexyl (see Adipates) Cancer Risk Ifr4 Cancer Cancer Group Risk (Mg/L) C 3,000 E — B2 — C — B2 3 D — D — D — B2 — C — D — D — C — D — 0 — B2 40 C — D — D — B2 500 D — B2 — B2 20 B2 0.2 D — Standards Longer- DWEL term HA (Child) (Mg/L) (Mg/L) 20,000 20,000 3 5 — — 800 2,000 — — — — 4,000 — 1,000 300 300 5,000 300 800 3,000 9,000 3,000 9,000 4,000 10,000 5,000 9,000 3,500' — — 700 400 1,000 400 3,000 600 2,000 2,000 — 100 30 — — 10 30 2 0.5 30,000 — and Health Advisories URH MCL/MCLG -STA Lev* (Mg/L) (Mg/I 400 / 400 — — — 0.3/0 — — — 0.2/0 3 — — — — — — — /O — — — Superfund 3 Removal R- Action ;1 Level -) (Mg/L) 4,000 3 0.3 800 3 — 4,000 300 300 300 600 / 600 3,000 3,000 600 / 600 — 3,000 75 / 75 750 750 — — — — 5/0 40 7/7 70 5,000 3,500 40 70 70 / 70 400 400 100 / 100 600 600 5/0 — — — 5/0 — — /O — — — — — 500 30 5 10 0.2 30,000 Word-Searchable Version - Not a true copy ------- NUMERIC REMOVAL ACTION LEVELS FOR CONTAMINATED DRINKING WATER SITES PRIMARY DRINKING WATER STANDARDS AND HEALTH ADVISORIES May 1993 Chemical ORGANICS CAS # Diethy Ihexy 1 phthalate 117817 Dimethrin 70382 Dimethyl methylphosphonate 756796 Dimethyl phthalate 131113 DIMP (Diisopropylmethylphosphonate) 1445756 Dinitrobenzene(l,3-) 99650 Dinitrotoluene (2,4-) 121 142 Dinitrotoluene (2,6-) 25321 146 Dinitrotoluene, tg> (2,6- & 2,4-) — Dinoseb 88857 Dioxanep-(l,4-) 123911 Dioxin (see 2,3,7,8-TCDD) Diphenamid 957517 Diphenylamine 122394 Diquat 85007 Disulfoton 298044 Dithiane(l,4-) 505293 Diuron 330541 Endothall 145733 Endrin 72208 Epichlorohydrin 106898 Ethylbenzene 100414 Ethylene dibromide (1,2-) (EDB) 106934 Ethylene dichloride (see 1,2-Dichloroethane) Ethylene gly col 107211 Ethyl ether 60297 Ethylene thiourea (ETU) 96457 Cancer Risk Ifr4 Cancer Cancer Risk Group (ug/L) B2 300 D — C 700 D — D — D — — — — — B2 5 D — B2 700 D — D — D — E — D — D — D — D — B2 400 D — B2 0.04 D — — — B2 30 Standards and Health Advisories Longer- DWEL term HA MCL/MCLG (Child) (ug/L) (ug/L) (ug/L) 700 — 6/0 10,000 10,000 — 7,000 2,000 — 350,000' — — 3,000 8,000 — 5 40 — 100 300 — 40 400 — — — — 40 10 7/7 — — — 1,000 300 — 1,000 300 — 80 — 20 / 20 1 3 — 400 400 — 70 300 — 700 200 100/100 10 3 2/2 70 70 Treat. Tech. / 0 3,000 1,000 700/700 — — 0.05/0 40,000 6,000 — 7,000s — — 3 100 — Superfund URTH Removal Action -STAR- Level Level (Mg/L) (Mg/L) — 300 — 10,000 — 2,000 — 350,000 — 3,000 — 5 — — — — — 5 — 10 — 700 — 300 — 300 — 80 — 1 — 400 — 70 — 200 — 3 70 70 1,000 1,000 0.05 0.05 — 6,000 — 7,000 — 3 Word-Searchable Version - Not a true copy ------- NUMERIC REMOVAL ACTION LEVELS FOR CONTAMINATED DRINKING WATER SITES PRIMARY DRINKING WATER STANDARDS AND HEALTH ADVISORIES May 1993 Chemical ORGANICS CAS # Fenamiphos 22224926 Fluometuron 2164172 Fluorene 86737 Fluorotrichloromethane (Freon-1 1 ) 75694 Fonofos 944229 Formaldehyde 50000 Freon-1 1 (see Fluorotrichloromethane) Freon-12 (see Dichlorodifluoromethane) Freon 113(1,1 ,2-Lrichloro- 76 1 3 1 1 ,1 ,2-trifluoroethane) Glyphosate 1071836 Heptachlor 76448 Heptachlor epoxide 1024573 Hexachlorobenzene 1 1 874 1 Hezachlorobutadiene 87683 Hexachlorocyclohexane, gamma (see Lindane) Hexachlorocyclophentadiene 77474 Hexachloroethane 67721 Hexane(n-) 110543 Hexazinone 51235042 HMX (Octahydro-l,3,5,7-tetranitro- 3691410 1,3,5,7-tetrazocine) Idenol[l,2,3-c,d]pyrene 193395 Isophorone 78591 Isoprophyl methylphosphonate 6838933 Isopropylbenzene (Cumene) 88828 Kerb (see Pronamide) Lindane (Hexachlorocyclohexane, gamma) 58899 Cancer Risk 104 Cancer Cancer Group Risk (ug/L) D — D — D — D — D — Bl — — — D — B2 0.8 B2 0.4 B2 2 C — D — C — D — D — D — B2 — C 4,000 D — — — C — Standards and Health Advisories Longer- DWEL term HA MCL/MCLG (Child) (ug/L) (ug/L) (ug/L) 95 — 400 2,000 — 1,400 — — 10,000 3,000 — 70 20 — 5,000 5,000 — 1,100,000' — — 4,000 1,000 700/700 20 5 0.4/0 0.4 0.1 0.2/0 30 50 1/0 70 100 —11 200 — 50/50 40 100 — — 4,000 — 1,000 3,000 — 2,000 5,000 — — — 0.4/0 7,000 15,000 — 4,000 30,000 — l,400a — — 10 30 0.2/0.2 Superfund URTH Removal -STAR- Action Level Level (Mg/L) (Mg/L) — 5 — 400 — 1,400 — 3,000 — 20 — 5,000 — 1,100,000 — 1,000 0.8 0.8 0.4C 0.4 — 2 — 70 — 200 — 40 — 4,000 — 1,000 — 2,000 — 0.4 — 7,000 — 4,000 — 1,400 2 2 Word-Searchable Version - Not a true copy ------- NUMERIC REMOVAL ACTION LEVELS FOR CONTAMINATED DRINKING WATER SITES PRIMARY DRINKING WATER STANDARDS AND HEALTH ADVISORIES May 1993 Chemical ORGANICS CAS # Malathion 121755 Maleic hy drazide 123331 MCPA (4-Chloro-2-methylphenoxy)-acetic 94746 acid Methomyl 16752775 Methoxychlor 72435 Methyl bromide (see Bromomethane) Methyl chloride (see Chloromethane) Methyl ethyl ketone (2-Butanone) 78933 Methyl parathion 298000 Methyl tert butyl ether 1 634044 Methylene bromide (see Dibromomethane) Methylene chloride (see Dichlorom ethane) Metolachlor 51218452 Metribuzin 21087649 Monochloroacetic acid (Chioroacetic 79 1 1 8 acid) Monochlorobenzene (Chiorobenzene) 108907 Naphthalene 91203 Nitroguanidine 556887 Nitrophenols p- 25154556 Octachlorocamphene (see Toxaphene) Oxamyl 23135220 Paraquat 1910425 Pentachloronitrobenzene (PCNB) 82688 Pentachlorophenol 87865 Perchloroethylene (see Tetrachloroethylene) Phenol 108952 Cancer Risk 104 Cancer Cancer Group Risk (ug/ D — D — E — D — D — Da — D — D — C — D — — — D — D — D — D — E — E — C1 — B2 30 D — Standards and Health Advisories DWEL L) (Mg/L) 800 20,000 50 900 200 21,000' 9 200 5,000 900 70a 700 100 4,000 300 900 200 100a 1,000 20,000 Longer- term HA MCL/MCLG (Child) (Mg/L) (Mg/L) 200 — 5,000 — 100 — 300 — 50 40 / 40 — — 30 — 500 — 2,000 — 300 — — — 2,000 100/100 400 — 10,000 — 800 — 200 200/200 50 — — — 300 1/0 6,000 — Superfund URTH Removal -STAR- Action Level Level (Mg/L) (ug/L) — 200 — 5,000 — 50 — 300 50 50 — 21,000 — 9 — 200 — 2,000 — 300 — 70 700 700 — 100 — 4,000 — 300 — 200 — 50 — 100 30 30 — 6,000 Word-Searchable Version - Not a true copy ------- NUMERIC REMOVAL ACTION LEVELS FOR CONTAMINATED DRINKING WATER SITES PRIMARY DRINKING WATER STANDARDS AND HEALTH ADVISORIES May 1993 Chemical ORGANICS CAS # Picloram 1918021 Polychlorinated biphenyls (PCBs) 1 336363 Prometon 1610180 Pronamide (Kerb) 23950585 Propachlor 1918167 Propazine 139402 Propham 122429 Pyrene 129000 RDX (Hexahydro-l,3,5-trmitro-l,3,5-tnazme) 121824 Simazine 122349 Styrene 100425 T (2,4,5-) 93765 Tackle (see Acifluorfen) TCDD (2,3,7,8-) (v) (Dioxm) 1746016 Tebuthiuron 34014181 Temik (see Aldicarb) Terbacil 5902512 Terbufos 13071799 Tetrachloroethane (1 ,1 ,1 ,2-) 630206 Tetrachloroethane (1 ,1 ,2,2-) 79345 Tetrachloroethylene (Perchioroethyiene) 1 27 1 84 Toluene 108883 Toxaphene (Octachlorocamphene) 8001352 TP (2,4,5-) (2(2,4,5-Tnchlorophenoxy- 93721 propionic acid) Cancer Risk 104 Cancer Cancer Group Risk (ug/ D — B2 0.5 D — C — D — C — D — D — C 30 C — C — D — Standards and Health Advisories DWEL L) 2,000 — 500 3,000 500 700 600 1,100 100 200 7,000 350 B2 0.00002 0.00004 D — E — D — C 100 Ca 20a B2a 70 D — B2 3 D — 2,000 400 5 1,000 — 500 7,000 3 300 Longer- term HA MCL/MCLG (Child) 700 500 / 500 1 0.5/0 200 — 800 — 100 — 500 — 5,000 — — — 100 — 70 4/4 2,000 100/100 800 — 0.00001 0.00003/0 700 — 300 — 1 — 900 — — — 1,000 5/0 2,000 1,000/1,000 — 3/0 70 50 / 50 Superfund URTH Removal -STAR- Action Level Level (Mg/L) (Mg/L) — 700 0.5 0.5 — 200 — 800 — 100 — 500 — 600 — 1,100 — 100 — 40 1,000 1,000 — 350 — 0.00003 — 700 — 300 — 1 — 900 — 2 70 70 — 2,000 3 3 70 70 Trichloroacetaldehyde (Chloral) see Chloral hydrate (hydrated form of trichloroacetaldehyde) Trichloroacetic acid 76039 Trichlorobenzene (1,2,4-) 120821 C — D — 1,300 400 4,000 —7100 100 70/70 — 1,000 — 100 Word-Searchable Version - Not a true copy ------- NUMERIC REMOVAL ACTION LEVELS FOR CONTAMINATED DRINKING WATER SITES PRIMARY DRINKING WATER STANDARDS AND HEALTH ADVISORIES May 1993 Chemical ORGANICS CAS # Trichlorobenzene (1,3,5-) 108703 Trichloroethane (1,1,1-) 71556 Trichloroethane (1 ,1 ,2-) 79005 Trichloroethylene (Tnchioroethene) 79016 Trichloromethane (see Chloroform) Trichlorophenol (2,4,6-) 88062 Trichlorophenoxypropionic acid (2(2,4,5-)) (see 2,4,5-TP) Trichloropropane ( 1 ,2,3-) 96 1 84 l,l,2-Trichloro-l,2,2-trifluoroethane (see Freon 113) Trifluralin 1582098 Trinitroglycerol 55630 Trinitrotoluene (2,4,6-) 1 1 8967 Vinyl chloride 75014 Vydate (see Oxamyl) Xylenes (mixed) 1 3 30207 Cancer Risk Ifr4 Cancer Cancer Risk Group (Mg/L) D — D — C — B2 300 B2 300 B2 — C — — — C 100 A 1.5 D — Standards Longer- DWEL term HA (Child) (ug/L) (ug/L) 200 600 1,000 40,000 100 400 300 — — — 200 600 300 80 — 5 20 20 — 10 60,000 40,000 and Health Advisories URT MCL/MCLG -S1A Lev (Mg/L) (Mg/ — — Superfund 13 Removal Action iR- Level el (ug/L) L) 200 200/200 1,000 1,000 5/3 — 30 5/0 300 300 — — — — — — — — — — 2/0 2 300 200 80 5 20 2 10,000/10,000 40,000 40,000 1 Based on data from IRIS or HEAST in the absence of a published U.S. EPA, Office of Water value 'Technical Grade (tg); 2,4- and 2,6-Dinitrotoluene are likely to occur alone : Based on special considerations Word-Searchable Version - 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