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Home My WebLink AboutDEQ-CFW_00004161This SOP provided by the Classifications and Standards Unit, DWQ Attachment A, EMC Agenda Item 08-48 A-1 The Division of Water Quality (DWQ) Standard Operating Procedure (SOP) for Reviewing Groundwater Standards Established Pursuant to 15A NCAC 02L.0200 Administrative Code Rule In accordance with "Classifications and Water Quality Standards Applicable to the Groundwaters of North Carolina�' 0 5A NCAC 02L .0202 (d)), the groundwater quality standards shall be established as the least of. 1 . Systemi'c threshold concentration calculated as follows: [Reference Dose (mg/kg/day) x 70 kg (adult body weight) x Relative Source Contribution (0.10 for inorganics; 0.20 for organics)]/[21iters/day (avg. water consumption)]; 2. Concentration which corresponds to an incremental lifetime cancer risk of I x 10-6; 3. Taste threshold limit value; 4. Odor threshold limit value; 5. Maximum contaminant level; or 6. National secondary drinking water standard. The rule further states that, "The following references, in order of preference, shall be used in establishirrul concentrations of substances which correspond to levels described in Paragraph (d) of this Rule": 1. Integrated Risk Information System (U.S. EPA) 2. Health Advisories (U.S. EPA Office of Drinking Water) 3. Other health risk assessment data published by the U.S. EPA 4. Other appropriate, published health risk assessment data, and scientifically valid peer -reviewed published toxicological data. I Procedure 1. Calculate systemic threshold concentration following the equation in the 2L rule: [Reference Dose (RfD) (mg/kg/day) x 70 kg (adult body weight) x Relative Source Contribution (0. 10 for inorganics; 0.20 for organics)]/ [21iters/day (avg. water consumption)]. Obtain the RfD from the following sources listed in joriori1y orde , (for more information on these sources of information, see section below "References for Toxicity Values"): 1. EPA Integrated Risk Information System (IRIS) 2. EPA Health Advisories 3. Other health risk assessment data published by the U.S. EPA, such as, but not limited to: L EPA Region 9 Preliminary Remediation Goal (PRG) Toxicity Values ii. EPA Provisional Peer Reviewed Toxicity Values (PPRTVs) iii. EPA Health Effects Assessment Summary Tables (HEAST, 1997) 4. Other appropriate, published health risk assessment data, and scientifically valid peer - reviewed published toxicological data. L Agency for Toxic Substances and Disease Registry (ATSDR) Chronic oral minimal risk levels (MRLs) ii. California EPA (CalEPA) Public Health Goals (PHGs) iii. Other published relevant toxicological data. OEQ-CFVV_00004161 P I'M 1, Page 2 of 4 A-2 0 MI M MOM This narrative is Earesented by the following equation: I X 10-6 Risk x 1 x 70 Kg x 1 day = X mg/L CSF (Risk/mg/Kg-day) 2L 179--MIR M, priori1y order: 1 X 10-6 1 . EPA integrated Risk Information System (IRIS): (Cancer risk levels for I x 10-' to risk for oral ex osure provided). Calculate I X 10-6 risk using the following equation: 1 x 1 OT risk level (mg/L) = 1 x 104 risk level (mg/L) x 0.01 2. EPA Health Advisories: (Cancer risk levels for 1 x 10-4 risk for oral exposure sometimes provided). Calculate t X 10"6 risk for oral exposure using the following equation: 1 X 10-6 risk level (mg/L) = 1 X 104 risk level (mg/L) x 0.01 3. Other health risk assessment data published by the U.S. EPA i. EPA (currently Region 9) PRG Toxicity Values (Cancer Slope Factors for oral exposure (CSFs) provided). Calculate I x 10-6 risk level for oral exposure using a CSF according to the equation above. I EPA HEAST (CSFs for oral exposure provided). o Convert to 1 X 10-6 risk level using equation above. 4. Other appropriate, published health risk assessment data, and scientifically valid peer -reviewed published toxicological data. M. Check the following reference for taste threshold values: M i. Young, W.F., Horth, H., Crane, R., Ogden, T. and Arnott, M. 1996. Taste and Odour Threshol4i Concentrations of Potential Potable Water Contaminants. Water Research, 30:2, pp.331-340. * Record the "geometric mean taste threshold concentration". ii. Other appropriate, scientifically valid peer -reviewed published data for taste threshold values. 4. Check the following references for odor threshold values: i. Young, W.F., Horth, H., Crane, R., Ogden, T. and Arnott, M. 1996. Taste and Odour ThreshoU Concentrations of Potential Potable Water Contaminants. Water Research, 30:2, pp.331-340 0 Record the "geometric mean odor threshold concentration". I Amoore, J.E. and Hautala, E. 1983. Odor as an Aid to Chemical Safety; Odor Thresholds Compared with Threshold Limit Values and Volatilities for 214 Industrial Chemicals in Air and Water Dilution. Journal ofApplied Toxicology, Volume 3, No. 6, 1983. Record the "water odor threshold7 but do not record the value if it is listed in parentheses (these values are considered to be very uncertain). iii. Other appropriate, scientifically valid peer -reviewed published data for odor threshold values. III !i I - - ! I IMF! 111 11 111111111111111111 1111111II(WE (0go IQ K401111 M 01-:146go gAmbgdoww iq� ii� 1, 111,1�� n7mrInn 11111; DEQ-CFW-00004162 Groundwater Standards SOP A-4 Page 4 of 4 Recommendations and Public Input Processes The DWQ will proceed through rulemaking and public input processes in accordance with North Carolina General Statute (NCGS) 150B to revise and establish groundwater standards. Public input opportunities will always be offered, at a minimum, in accordance with the requirements outlined in NCGS 150. Before presenting a groundwater standard proposal to the Groundwater Committee of the EMC to commence with rulemaking, the DENR DWQ will notify the NC Department of Health and Human Services Division of Public Health (DPH) and the NC Department of Environment and Natural Resources Division of Waste Management (DWM) by a letter that includes enough information to provide a clear indication of the basis and process used to determine the proposed standard(s). The supporting information used to develop the proposal will also be included: if a reference is available on the internet, the link will be provided; if a reference is not available on the internet, the document will be provided. DWQ will make every effort to send letter notification to DPH and DWM thirty (30) days prior for single standards and sixty (60) days prior for proposals involving more than one standard. Information on all proposals received by DPH and DWM will be treated as sensitive, internal material not to be distributed. The purpose of the written notice is to request the DPH and DWM to review and (�,rovide comment on 2L standards the rulemaking process and prior to the APA public comment period. Comment and/or information ar(.- to be provided to DWQ on the specific proposal within the timeftame requested. DWQ will consider the provided information prior to the DWQ decision to make a recommendation to the Groundwater Committee for rulemaking. re)rocess for revising and establishing groundwater standards. Therefore, there may be, at the judgment of the DWQ Director or at the agreement of the three agencies, a good reason to move forward to the Groundwater Committee of the EMC, or otherwise, with any specific proposal without the additional thirty -day or sixty-day comment period between the agencies, and the Director of DWQ may deem a shorter timeframe as appropriate. Nothing in this SOP document binds the DWQ or the Director's authorities established pursuant to the North Carolina Administrative Code. T�Tm'�'IV (I CM7A?175 elac screTion. or Tne *WQ and the for professional toxicological input on any potential or existing groundwater 5f?ndard. I ........... 1"To L recommendations and public input processes, prior to submitting the IMAC request to the DWQ Director. DEQ-CFW-00004164