NCG500354_Denial_20200214

p STATE'w
ROY COOPER
Governor -
MICHAEL S.REGAN
Secretary
S.DANIEL SMITH NORTH CARouNA
Director Environmental Quality
February 14, 2020
To: Charles Weaver
NPDES Compliance and Expedited Pennitting
From: Hannah Headrick ,�{
Aquatic Toxicity Branch
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 predict the use of ChemTreat BL 4350 and ChemTreat BL 1541, at the stated
dosage rates, will 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. is
acceptable.
Calculations predict the use of ChemTreat BL 1258 and Sulfuric Acid products will 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. is not acceptable.
Please note that we assessed these products with the limited information provided,
therefore this assessment might not give the most accurate evaluation of these products.
For instance, we used the most conservative number for the IWC, half-life, and decay rate
for each chemical for protective purposes due to the limited information received. If more
accurate information for these values can be provided, we will be glad to reassess these
products and the proposed discharge to Morehead City Harbor.
There are other options as well. The facility could also perform a Chronic multi-
concentration Ceriodaphnia 7-day reproduction test with these products.
Please iet us know if you have questions.
North Carolina Department of Environmental Quality I Division of Water Resources I Water Sciences Section
4401 and 4405 Reedy Creek Road 1 1621 Mail Service Center I Raleigh,North Carolina 27699-1621
Pa lyd,M`A lEmmmmoM1 ia�m 919.743.8400

Dishcharger Name Slurry Pavers, Inc.
PERMIT#: NCG500354/002
RECEIVING STREAM: Morehead City Harbor
7Q10(cfs): 0.00
I.W.C.%: 100.00
PRODUCT: ChemTreat BL 1258
ACTIVE INGREDIENT: Active Ingredient
HALF LIFE(DAYS): 0.00 STEADY STATE DISC CONC 30.0132
LC50/EC50 OF SELECTED TOX DATA(MG/342 DEGRADATION FACTOR: 1.000
DECAY RATE: 0.0000 APPLICATION FACTOR: 0.050
DOSAGE RATE(GRAMS/DAY): 113.6
AVG DAILY DISCHARGE(MGD): 0.001 INSTREAM BIOCIDE CONC: 30.0132
VOLUME OF SYSTEM (MIL. GAL'S): 0.001 REGULATED LIMITATION: 17.1
PASS/FAIL: FAIL
PRODUCT: ChemTreat BL 4350
ACTIVE INGREDIENT: Active Ingredient
HALF LIFE(DAYS): 0.00 STEADY STATE DISC CONC 25.0145
LC50/EC50 OF SELECTED TOX DATA(MG/11708 DEGRADATION FACTOR: 1.000
DECAY RATE: 0.0000 APPLICATION FACTOR: 0.05
DOSAGE RATE(GRAMS/DAY): 94.68
AVG DAILY DISCHARGE (MGD): 0.001 INSTREAM BIOCIDE CONC: 25.0145
VOLUME OF SYSTEM (MIL. GAL'S): 0.001 REGULATED LIMITATION: 85.4
PASS/FAIL: PASS
PRODUCT: ChemTreat BL 1541
ACTIVE INGREDIENT: Active Ingredient
HALF LIFE(DAYS): 0.00 STEADY STATE DISC CONC 15.0013
LC50/EC50 OF SELECTED TOX DATA(MG/1654.5 DEGRADATION FACTOR: 1.000
DECAY RATE: 0.0000 APPLICATION FACTOR: 0.05
DOSAGE RATE(GRAMS/DAY): 56.78
AVG DAILY DISCHARGE(MGD): 0.001 INSTREAM BIOCIDE CONC: 15.0013
VOLUME OF SYSTEM (MIL. GAL'S): 0.001 REGULATED LIMITATION: 32.725
PASS/FAIL: PASS
PRODUCT: Sulfuric Acid
ACTIVE INGREDIENT: Active Ingredient
HALF LIFE (DAYS): 0.00 STEADY STATE DISC CONC 269.4848
LC50/EC50 OF SELECTED TOX DATA(MG/149 DEGRADATION FACTOR: 1.000
DECAY RATE: 0.0000 APPLICATION FACTOR: 0.05
DOSAGE RATE(GRAMS/DAY): 1020
AVG DAILY DISCHARGE (MGD): 0.001 INSTREAM BIOCIDE CONC: 269.4848
VOLUME OF SYSTEM (MIL. GAL'S): 0.001 REGULATED LIMITATION: 2.45
PASS/FAIL: 7� i