Brunswick lands necessary discharge permit to produce RO-treated water

Reverse osmosis discharge concentrate will travel along a planned 4-mile pipeline from the Northwest Water Treatment Plant to a new outfall on the Cape Fear River. (Port City Daily photo/Courtesy Brunswick County)

BRUNSWICK COUNTY — After a delayed environmental permitting schedule, Brunswick County has obtained the required National Pollutant Discharge Elimination System (NPDES) permit to discharge reverse osmosis concentrate into the Cape Fear River.

With the modified permit now in hand, Brunswick County can officially move ahead with its $90 million low-pressure reverse osmosis upgrade plans at the Northwest Water Treatment Plant. The approval comes a couple of weeks ahead of when the Department of Environmental Quality (DEQ) first said it expected to make a decision on the permit.

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DEQ’s earlier approval does not move up the project schedule. Meagan Kascsak, the county’s spokesperson, said the March 5 bid due date will remain the same. She pointed out that ultimately, the decision to award a bid to construct reverse osmosis upgrades is up to county commissioners.

Out of the three bid alternatives still under consideration including reverse osmosis upgrades, the soonest RO-treated water could become available is November 2022, with final completion of this option by February 2023. The latest it could become available is August 2023, with final completion by November 2023.

The NPDES permit is not actually a separate permit from the county’s existing permit that allows it to discharge into Hood Creek, rather, it’s a modification of the existing permit to allow for the reverse osmosis upgrades and planned expansion.

Concentrate pipeline

Under the NPDES permit, issued by the DEQ Feb. 13, the county may discharge a maximum of 5 million gallons a day (MGD) from a new outfall. The new outfall will only contain reverse osmosis concentrate (not to be mixed with wastewater created via conventional water treatment methods already located on site).

This will be accomplished through a planned discharge concentrate pipeline that will stretch 4-miles from the Northwest Water Treatment Plant, under Mt. Misery Road, and release discharge into the Cape Fear River. Current conventional treatment methods release an average of 1.5 MGD of wastewater into a tributary of Hood Creek.

Pilot testing in April 2018 conducted by the county’s consultant, CDM Smith, revealed reverse osmosis equipment could remove more than 90% of PFAS tested. Last year, treated water at the Northwest Water Treatment Plant contained an average of 115 parts per trillion (ppt) of PFAS tested. Total PFAS was as high as 414 ppt in treated water in a sample collected Aug. 22 at the plant.

A nationwide study released late last month ranked a water sample collected at Belville Elementary School in Brunswick County at the top of its list, which included 44 metropolitan areas among 31 states. That sample contained 186 ppt total PFAS tested. More than 5,000 PFAS compounds are known to persist in the environment, but testing methodology for only a few dozen has been developed at this point.

Related: Brunswick County to spend $1.2 million replacing 45-year-old groundwater filters

Delays, earlier concerns

Though the county first announced RO-treated water would arrive by December 2021, prospective bidders could not accommodate the county’s aggressive construction schedule, so completion deadlines were pushed back. Also, the DEQ delayed its permitting process, according to the county. 

In December, the Southern Environmental Law Center (SELC), writing on behalf of local environmental advocacy groups including Cape Fear River Watch, Clean Cape Fear, and the North Carolina Coastal Federation, commented on the DEQ’s draft NPDES permit. 

Before diving into the issues, SELC first pointed out the groups were supportive of the county’s plans and did not intend to delay or prevent the plant’s progress. 

The SELC’s main concern, generally speaking, is that the DEQ would allow the county to release an unknown and unspecified amount of PFAS back into the Cape Fear River, while those discharges remained unlisted and unpermitted on the county’s NPDES permit.

The county’s omission of PFAS in its NPDES concentrate discharge application qualifies as a Clean Water Act violation, as does DEQ’s permission of allowing toxic substances to enter Class C waters, the SELC asserted in its comments.

According to the DEQ, monitoring frequency for PFAS compounds has been increased to quarterly, rather than semiannually, as first proposed under the draft NPDES.

Read the full discharge permit below:

NC0057533_Permit (Issuance)_20200213 by Johanna Ferebee Still on Scribd


Send tips and comments to Johanna Ferebee Still at johanna@localvoicemedia.com

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