National Ground Water Association CEO Terry S. Morse, CAE, CIC, has issued the following statement in response to the NPDES PFAS: Interim Strategy for PFAS in Federally Issued National Pollutant Discharge Elimination System Permits.
“We at NGWA are encouraged by the PFAS NPDES Regional Coordinators Committee’s new interim strategy to better understand and mitigate the risk in PFAS in wastewater and stormwater discharge.
“As future strategies and guidance are drafted, NGWA urges the EPA and its partners to be thoughtful of how PFAS transmissions from wastewater and stormwater into our nation’s surface water in turn affect our groundwater supply.
“The United States — and the world — is highly dependent on groundwater as a source of clean drinking water and for crop irrigation. PFAS contamination in groundwater must be a top priority for future study and actions by the EPA.”
For more information or additional comments, please contact Ben Frech at bfrech@ngwa.org or call (614) 898-7791, ext. 1570.
Media Background: Stormwater Infiltration Disposal Potentially Impacting Groundwater Supplies
by Chuck Job, NGWA Regulatory Affairs Manager, cjob@ngwa.org
PFAS (per- and polyfluoroalkyl substances) have been identified as stormwater pollutants in urban, residential, commercial, and industrial settings [1] [2]. The Clean Water Act National Pollutant Discharge Elimination System (NPDES) stormwater program regulates stormwater discharges from municipal separate storm sewer systems (MS4s) as well as from construction and industrial activities. Operators of these sources might be required to obtain an NPDES permit before they can discharge stormwater. This permitting mechanism is designed to prevent stormwater runoff from washing harmful pollutants into local surface waters. A principal stormwater control measure that U.S. Environmental Protection Agency has identified is the infiltration of stormwater into the subsurface, potentially affecting groundwater quality.
At least an estimated 1525 MS4 permittees may be coincident with a groundwater-supplied public community water system (CWS), which, collectively, serve 36.4 million people, based on matching place names between two databases [3].These MS4 permittees equal 22 percent of the MS4s that EPA identified in 2009, which may not include many small MS4s identified since that time. Communities relying on groundwater supply adjacent to MS4 communities using stormwater infiltration to protect surface water quality may also be affected. At least 254 additional groundwater-supplied CWSs (and perhaps more not identified in this place name analysis) serving an additional six million people may be adjacent to many of these MS4 permittees.
These counts do not include industrial stormwater dischargers that are separately permitted, nor do they count larger surface water-supplied systems that have groundwater wells for peak demand, backup, or emergency water supply purposes. Nearly 70 percent of the coincident groundwater-supplied community water systems are medium-size to small communities serving 20,000 or fewer people. This count does not include the many private well owners relying on groundwater adjacent to these towns. Two-thirds of these community groundwater systems serve 10,000 or fewer people. These small communities have fewer resources and technical capability to address future groundwater quality problems. Thirty states have from 20 up to 100 percent of their MS4 permittees that are coincident with groundwater-supplied community water systems. These percentages and populations may increase if surface water-supplied CWS with back-up groundwater wells can be identified.
[1] Deeb, Rula; Jennifer Arblaster; Adam Questad; and Brandon Steets. 2020. PFAS in Surface Water; The state of the practice. Published online in Stormwater. https://www.stormh2o.com/home/article/21144763/pfas-in-stormwater-the-state-of-the-practice
[2] U.S. Environmental Protection Agency. 2020. New Interim Strategy Will Address PFAS Through Certain EPA-Issued Wastewater Permits; Press Release of Nov 30, 2020. https://www.epa.gov/newsreleases/new-interim-strategy-will-address-pfas-through-certain-epa-issued-wastewater-permits
[3] U.S. Environmental Protection Agency, Stormwater Branch, communication of August 26, 2020. Nationwide inventory of MS4 permittees in 2009. The inventory of permittees does not include any Phase II communities that were brought into the program as part of the 2010 census; U.S. Environmental Protection Agency. 2020. Government Performance Results Act Drinking Water Tool. GPRA [Drinking Water] Inventory Report. https://obipublic.epa.gov/analytics/saw.dll?PortalPages
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The National Ground Water Association is a not-for-profit professional society and trade association for the global groundwater industry. Our members around the world include leading public and private sector groundwater scientists, engineers, water well system professionals, manufacturers, and suppliers of groundwater-related products and services. The Association’s vision is to be the leading groundwater association advocating for responsible development, management, and use of water.