Fairfax County

NPDES permit VA0025364 · Major POTW · effective, expires 2030-05-31 · EPA's file as of 2026-09-19

Check this month's numbers before you file
Watch this permit — $79 a month. Every Monday, from EPA's newest files: the next report due and when, whether EPA's file holds your last one, any change to this permit's limits or status, and the renewal date.

EPA's record, 2025-09-01 to 2026-08-31

0values over a limit
0required values missing, on 0 form(s)
1of 11 forms filed late

Last period with anything received: 2026-07-31.

Reporting

Reports are due about 10 days after each monitoring period ends (read off this permit's own late-day counts in EPA's filings).

Limits in force (32)

OutfallParameterStatisticLimitMonths
001Oxygen, dissolved [DO]MINIMUM >= 6 mg/L all year
001pHMINIMUM >= 6 SU all year
001pHMAXIMUM <= 9 SU all year
001Solids, total suspendedMO AVG <= 6 mg/L all year
001Solids, total suspendedWKLY AVG <= 9 mg/L all year
001Solids, total suspendedMO AVG <= 1522 kg/d all year
001Solids, total suspendedWKLY AVG <= 2282 kg/d all year
001Solids, total suspendedMO AVG report only all year
001Nitrogen, total [as N]MO AVG report only all year
001Nitrogen, ammonia total [as N]MO AVG <= 1 mg/L Apr, May, Jun, Jul, Aug, Sep, Oct
001Nitrogen, ammonia total [as N]MO AVG <= 2.1 mg/L Jan, Feb, Mar, Nov, Dec
001Nitrogen, ammonia total [as N]WKLY AVG <= 1.5 mg/L Apr, May, Jun, Jul, Aug, Sep, Oct
001Nitrogen, ammonia total [as N]WKLY AVG <= 3.1 mg/L Jan, Feb, Mar, Nov, Dec
001Nitrogen, ammonia total [as N]MO AVG <= 254 kg/d Apr, May, Jun, Jul, Aug, Sep, Oct
001Nitrogen, ammonia total [as N]WKLY AVG <= 380 kg/d Apr, May, Jun, Jul, Aug, Sep, Oct
001Nitrogen, Kjeldahl, total [as N]MO AVG report only all year
001Nitrite + Nitrate total [as N]MO AVG report only all year
001Phosphorus, total [as P]MO AVG <= .18 mg/L all year
001Phosphorus, total [as P]WKLY AVG <= .27 mg/L all year
001Phosphorus, total [as P]MO AVG <= 45.6 kg/d all year
001Phosphorus, total [as P]WKLY AVG <= 68.5 kg/d all year
001Flow, in conduit or thru treatment plantMO AVG report only (alert) all year
001Flow, in conduit or thru treatment plantMAXIMUM report only (alert) all year
001E. coliGEO MEAN <= 126 #/100mL all year
001Nitrogen, Total As NMO AVG <= 3 mg/L all year
001BOD, carbonaceous [5 day, 20 C]MO AVG <= 5 mg/L all year
001BOD, carbonaceous [5 day, 20 C]WKLY AVG <= 8 mg/L all year
001BOD, carbonaceous [5 day, 20 C]MO AVG <= 1286 kg/d all year
001BOD, carbonaceous [5 day, 20 C]WKLY AVG <= 2029 kg/d all year
001BOD, carbonaceous [5 day, 20 C]MO AVG report only all year
001BOD, carb-5 day, 20 deg C, percent removalMO AV MN >= 85 % all year
001Solids, suspended percent removalMO AV MN >= 85 % all year

Built from EPA's ECHO bulk files. EPA's file, not the permit document, is the source: read your permit. Check a report before you file it · All states