NCG500354_approval_20200220

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ROY COOPER
Governor
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MICHAEL S.REGAN
Secretary
S.DANIEL SMITH NORTH CARouNA
Director Environmental Quality
February 20, 2020
To: Charles Weaver
NPDES Compliance and Expedited Permitting
From: Hannah Headrick
Aquatic Toxicity Braril �
Subject: Biocide Use Review
Slurry Pavers, Inc.
NPDES #NCG500354/002
Carteret County
Slurry Pavers, Inc. has requested approval of four chemicals: ChemTreat BL 1258, ChemTreat
BL 4350, ChemTreat BL 1541, and Sulfuric Acid. These products will be discharged from its
Outfall 002 and in to the Morehead City Harbor.
Calculations predicted the use of ChemTreat BL 4350 and ChemTreat BL 1541, at the stated
dosage rates, would not cause toxic impacts to aquatic life in the receiving water body,
Morehead City Harbor. Therefore, the use of these products as proposed at Slurry Pavers, Inc.
was deemed acceptable.
We had previously denied the use of ChemTreat BL1258 and Sulfuric Acid since our
conservative calculations showed that the use of these chemicals would cause toxic impacts to
aquatic life in the receiving water body, Morehead City Harbor. However, David Callahan with
Asphalt Emulsion Industries, LLC has provided effluent analyses that show the use of these
chemicals in small doses is necessary to treat the effluent to meet the requirements of the
wastewater permit. Use of ChemTreat BL1258 is necessary to maintain proper total residual
chlorine levels (below 50ug/L)in the effluent. Use of Sulfuric Acid is necessary to maintain a
pH of 6.8-8.5 in the discharged effluent. Therefore, the use of ChemTreat BL1258 and Sulfuric
Acid by Slurry Pavers, Inc. is acceptable as long as Slurry Pavers, Inc. maintains the limits of its
permit.
North Carolina Department of Environmental Quality I Division of Water Resources I Water Sciences Section
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44D1 and 4405 Reedy Creek Road 1 1621 Mail Service Center I Raleigh North Carolina 2 76 9 9-1621
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