Environmental Services
Wastewater Treatment Permit Information
Permit and Process Information
The Arlington Water Pollution Control Plant operates under a Virginia Pollutant Discharge Elimination System (VPDES) permit, issued by the Virginia Department of Environmental Quality (DEQ). The permit for the incinerator operation also is issued by the DEQ. The basic permit requirements for the VPDES permit are outlined here. Future sludge land disposal will fall under EPA 503 regulations.
VPDES Permit Requirements
Parameter Minimum Monthly Average Maximum Flow 30.0 MGD pH 6.0 units 8.5 units CBOD5 5 mg/1 8 mg/1n TSS 6 mg/1 9 mg/1n Total Chlorine Disinfection 0.5 mg/1l Final Residual Chlorine 0.008 mg/l <0.1 mg/1u Fecal Coliform
(geometric mean)126/100 ml Dissolved Oxygen 6.0 mg/1 Total Phosphorus 0.18 mg/1 0.27 mg/1n Ammonia (Nov-March) 3.5 mg/1 4.2 mg/1n Ammonia (Apr-Oct) 1.0 mg/1 2.7 mg/1n
l No more than 36 exceptions per month allowed below 0.5 mg/l and none below 0.2 mg/l
n Maximum weekly averages
u No exceptions allowed and none above 1.0 mg/l
Note:
MGD = Million Gallons per Day
BOD5 = Biochemical Oxygen Demand, 5-day test
TSS = Total Suspended Solids
mg/l = milligrams per liter
ml = milliliters
Process Data - Annual Averages
(July 2000 - June 2001)
Average Daily Flow = 31.6 MGD
Primary Treatment:
Influent BOD5 221 mg/1 Influent TSS 215 mg/l Influent Phosphorous 3.96 mg/l Tertiary/Advanced Treatment (VPDES Permit Results):
Effluent BOD5 2.2 mg/l 99% cumulative removal Effluent TSS 1.4 mg/l 99.4% cumulative removal Effluent Phosp. 0.05 mg/l 99.4% cumulative removal Ferric Chloride Dosage to AWT = 30mg/1/day average Solids Handling:
Incineration was shut down as of March 23, 1998. Solids are currently dewatered by centrifuges, then stabilized with lime before they are hauled to a land application site.
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