DEQ-CFW_00004137

From: Moore, Sandra [SANDR&K8OORE]
Sent: 7/28/20107:55:35PN1
To: Clark, Alan [/o=NCMAIL/ou=Exchange Administrative Group (FYDIBOHF23SPDLT)/cn=Recipients/cn=Alan.Clark]
Subject: RE: PFCA Questions
Alan,
We have been asked in the past by Reginald Jordan to explain the difference between a groundwater standard and a
drinking water standard. People are most familiar with the federal drinking water standards and some make the
assumption that the groundwater standard and drinking water standard are the same. The question seems tokeep
coming up from various sources in regard to PFOA so we thought it would be good to put it in writing. Recendyvve
received a request from the assistant editor of the Pesticide & Toxic Chemical News (through Susan Massengale) to
explain how groundwater standards relate to drinking water standards. The Assistant Editor also wanted to know what
the next steps are for the Division of Water Quality once the NCSAB offers a final recommendation on PFOA.
Sandra
State Water Quality Standards Co -coordinator
Division ofWater Quality
NC Department of Environment and Natural Resources
1617 Mail Service Center, Raleigh, NC 27699-1617
Sandra. [e-mail]
Note: E-mail correspondence mmndfrorn this addressmay be subject to the North Carolina Public Records Low and may bedisclosed
to third parties.
From: Clark, Alan
To: Moore, Sandra
Cc: Manning, 3eff
Subject: RE: PFOA Questions
Sandra, that was avery well -written email. Imaunwondering—aredhequestiunsforyuuand[onnieconoinBfnmmdhe
SABmemben7
From: Moore, Sandra
Sent: Wednesday, 3uk/28,201012:42PM
T0:JOnUBn, Reginald
Cc: Brower, Connie; M8nning,]eff; Clark, Alan; Moore, Sandra; Remington, Nikki
Subject: PFOA Questions
Connie and I have received a number of questions concerning the Division of Water Quality's request for assistance from
the North Carolina Science Advisory Board (NCSAB) to perform a comprehensive evaluation of the toxicology of PFOA
and make recommendations onappropriate toxicity indices.
To make sure we are all on the same page, we offer the following information.
OEQ-CFVV_00004137

What the NCDENR Division of Water Quality needs from the NCSAB is a recommendation on an appropriate reference
dose (RfD) and/or a cancer slope factor (CSF) to use to calculate a groundwater qualitystandard in accordance with the
Groundwater Quality Regulations found in15ANQ\[UZL.OZOZ(d)( .
We are not requesting a recommendation for use in developing a NC drinking water standard, which is regulated under
the federal Safe Drinking Water Act and implemented by the NC Division of Environmental Health under Title 15A,
Subchapter 18Cofthe North Carolina Administrative Codes. Below isanexplanation ofthe difference between aNC
groundwater standard and a NCdrinking water standard (note that some folks have been using these interchangeably).
The Safe Drinking Water Act (SDWA) is the main federal law that ensures the quality of the nations drinking water (what
comes out the tap). Under the SDWA, the Environmental Protection Agency (EPA) sets drinking water standards, also
commonly referred toasfederal maximum contaminant levels orK4[Ls
. The EPA also oversees the states, localities, and water suppliers
who implement those standards. |nNC, the SD\NAisimplemented bythe NCDENRDivision ufEnvironmental
Health. N[DEHRules and Drinking Water Standards can befound ontheir web site at
The NC Division of Water Quality establishes groundwater standards and groundwater interim maximum allowable
concentrations (IMACs) in accordance with State Law (15A NCAC 2L .0202) in order to protect all groundwaters of the
state from being degraded and to protect itfor use asa current and future drinking water source. NC Groundwater
standards and |K4A[s are established using essentially the criteria asthe federal drinking water standards or M[is;
however, a major difference is that EPA has the authority to establish MCLs at higher risk levels that consider the cost of
treating the water, while the 2L groundwater standards are strictly health -based and do not consider the cost of
There is no federal or NC drinking water standard for PFOA. NC DWQ has established a groundwater interim maximurr
allowable concentration or IMAC for PFOA of 2 ug/L (ppb) in accordance with Groundwater Regulations found in 15A
Once the NC Science Advisory Board (NCSAB) offers a final recommendation on an RfD and/or CPF, the Division of Water
Quality (DWQ) will consider their recommendation and reevaluate the current PFOA groundwater IMAC of 2 ug/L
(ppb). Should the DWQ determine that the PFOA groundwater IMAC needs to be updated, it will act immediately to do
so. This process generally takes about three months.
We hope this information will help if you are receiving similar questions about the difference between a NC
groundwater standard and a NCdrinking water standard, what the DVVO's next steps will beonce the NCB\8offeo its
recommendation and what the timeline istoupdate the PFOA|MAC.
Please don't hesitate to call with any questions. Thanks for all of your help and support.
Candra and Connie
State Water Quality Standards Co -coordinator
Division ofWater Quality
NC Department of Environment and Natural Resources
1617M#il Service Center, Raleigh, NC27699-1617
Sandra. moore@ncdenr._g
Note: E-mmcorresponden ce to and from this address may be subject mthe North Carolina Public Records Low ondmay be disclosed
to third porties.
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