Get Full Government Meeting Transcripts, Videos, & Alerts Forever!
Get email alerts on the Water Quality Standards topic
No spam. Unsubscribe anytime.
DEQ proposes expanding Chesapeake Bay 'deepwater' boundary and to adopt EPA PFAS aquatic‑life criteria
Summary
DEQ staff recommended expanding the Chesapeake Bay deepwater designated use based on decades of monitoring showing summer stratification and low bottom‑water dissolved oxygen, and proposed incorporating EPA's PFOA and PFOS aquatic‑life criteria; the board authorized public comment and hearings on the triennial review.
DEQ staff on Nov. 18 presented proposed amendments to Virginia's water quality standards (triennial review under 9VAC25‑260) that would reshape how some areas of the Commonwealth's portion of the Chesapeake Bay are classified and regulated.
Dr. Tish Robertson, representing DEQ’s water quality standards program, said staff are recommending expanding the 'deepwater' designated use to include additional bay segments where long‑term monitoring shows persistent summer stratification and low bottom‑water dissolved oxygen (DO). "DEQ staff are recommending the expansion of the deepwater boundary to include areas that are currently not included in that designation, but have the physical features of deep water habitat," Robertson said. She showed multi‑decadal station data and said some stations show a picnic‑line frequency and low DO below that line nearly every sampling event, which supports applying a deepwater DO criterion (a lower DO criterion applies in deepwater and deep‑channel areas than in open‑water uses).
Another substantive proposal is to adopt EPA's 2024 nationally recommended aquatic‑life criteria for two PFAS chemicals, PFOA and PFOS. Robertson said EPA's criteria are expressed for water‑column concentrations and whole‑body tissue concentrations to protect freshwater organisms; DEQ staff converted values into parts per trillion for board review. "In 2024, EPA finalized nationally recommended criteria for 2 PFAS substances, perfluorooctanoic acid, PFOA, and perfluorooctanesulfonate, PFOS," she told the board.
Staff also proposed clarifying implementation language for Bay DO criteria (adding tenths for consistency) and updating copper biotic‑ligand model language to require agency‑approved procedures and to clarify that BLM‑based criteria supersede hardness‑based criteria where used.
DEQ recommended adding a DEQ‑authored technical support document to describe the justification for the deepwater expansion and requested authorization to proceed to public comment and hearing. The board moved to authorize the public‑comment and hearing process and voted to approve staff taking the item to public comment; no final numeric changes were adopted at the meeting.
What happens next: DEQ will publish the proposed rulemaking and technical support materials, accept public comment and hold hearings under the Administrative Process Act. The board also authorized staff to serve as hearing officer for the amendments.
