Washington Suburban Sanitary Commission - WSSC

NPDES permit MD0021741 · Major POTW · effective, expires 2028-03-31 · 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)
0of 23 forms filed late

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

Reporting

Reports are due about 28 days after each monitoring period ends (the most common figure among MD permits in EPA's filings — check your permit).

Limits in force (70)

OutfallParameterStatisticLimitMonths
001Oxygen, dissolved [DO]INST MIN >= 5 mg/L Feb, Mar, Apr, May
001Oxygen, dissolved [DO]INST MIN >= 5 mg/L Jan, Jun, Jul, Aug, Sep, Oct, Nov, Dec
001Oxygen, dissolved [DO]MO AV MN >= 5.5 mg/L Feb, Mar, Apr, May
001Oxygen, dissolved [DO]MO AV MN >= 5.5 mg/L Jan, Jun, Jul, Aug, Sep, Oct, Nov, Dec
001Oxygen, dissolved [DO]MN WK AV >= 6 mg/L Feb, Mar, Apr, May
001BOD, 5-day, 20 deg. CMX MO AV <= 9 mg/L Apr, May, Jun, Jul, Aug, Sep, Oct
001BOD, 5-day, 20 deg. CMX MO AV <= 30 mg/L Jan, Feb, Mar, Nov, Dec
001BOD, 5-day, 20 deg. CMX WK AV <= 14 mg/L Apr, May, Jun, Jul, Aug, Sep, Oct
001BOD, 5-day, 20 deg. CMX WK AV <= 45 mg/L Jan, Feb, Mar, Nov, Dec
001BOD, 5-day, 20 deg. CMX MO AV <= 2300 lb/d Apr, May, Jun, Jul, Aug, Sep, Oct
001BOD, 5-day, 20 deg. CMX MO AV <= 7500 lb/d Jan, Feb, Mar, Nov, Dec
001BOD, 5-day, 20 deg. CMX WK AV <= 3500 lb/d Apr, May, Jun, Jul, Aug, Sep, Oct
001BOD, 5-day, 20 deg. CMX WK AV <= 11300 lb/d Jan, Feb, Mar, Nov, Dec
001pHMINIMUM >= 6.5 SU all year
001pHMAXIMUM <= 8.5 SU all year
001Solids, total suspendedMX MO AV <= 30 mg/L all year
001Solids, total suspendedMX MO AV <= 30 mg/L all year
001Solids, total suspendedMX WK AV <= 45 mg/L all year
001Solids, total suspendedMX MO AV <= 7500 lb/d all year
001Solids, total suspendedMX WK AV <= 11300 lb/d all year
001Solids, total suspendedANNL MAX <= 2737500 lb/yr all year
001Solids, total suspendedMX MO AV <= 30 mg/L all year
001Solids, total suspendedMO TOTAL report only all year
001Nitrogen, total [as N]MX MO AV <= 3 mg/L Apr, May, Jun, Jul, Aug, Sep, Oct
001Nitrogen, total [as N]MX WK AV <= 4.5 mg/L Apr, May, Jun, Jul, Aug, Sep, Oct
001Nitrogen, total [as N]MX MO AV <= 770 lb/d Apr, May, Jun, Jul, Aug, Sep, Oct
001Nitrogen, total [as N]MO TOTAL report only all year
001Nitrogen, total [as N]MX WK AV <= 1150 lb/d Apr, May, Jun, Jul, Aug, Sep, Oct
001Nitrogen, total [as N]CUM TOTL <= 372776 lb/yr all year
001Nitrogen, total [as N]ANNL TOT report only Dec
001Nitrogen, total [as N]ANNL TOT report only all year
001Nitrogen, total [as N]ANNL TOT report only all year
001Nitrogen, total [as N]MO AVG report only Jan, Feb, Mar, Nov, Dec
001Nitrogen, total [as N]MO AVG report only Jan, Feb, Mar, Nov, Dec
001Nitrogen, organic total [as N]MO AVG report only all year
001Nitrogen, ammonia total [as N]MX MO AV <= 1.5 mg/L Apr, May, Jun, Jul, Aug, Sep, Oct
001Nitrogen, ammonia total [as N]MX MO AV <= 4.4 mg/L Jan, Feb, Mar, Nov, Dec
001Nitrogen, ammonia total [as N]MX MO AV <= 383 lb/d Apr, May, Jun, Jul, Aug, Sep, Oct
001Nitrogen, ammonia total [as N]MX MO AV <= 1124 lb/d Jan, Feb, Mar, Nov, Dec
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]MX MO AV report only all year
001Phosphorus, total [as P]MX MO AV report only all year
001Phosphorus, total [as P]MO TOTAL report only all year
001Phosphorus, total [as P]ANNL MAX <= 2737500 lb/yr all year
001Phosphorus, total [as P]ANNL TOT report only Dec
001Phosphorus, total [as P]ANNL TOT report only all year
001Phosphorus, total [as P]ANNL TOT report only all year
001Hardness, total [as CaCO3]MO AVG report only all year
001Hardness, total [as CaCO3]MO AVG report only all year
001Copper, total recoverableMO AVG report only all year
001Flow, in conduit or thru treatment plantMO AVG report only all year
001Flow, in conduit or thru treatment plantDAILY MX report only all year
001Chlorine, total residualDAILY MX <= .1 mg/L all year
001EnterococciMAXIMUM <= 35 MPN/100mL all year
001Phosphorous, in total orthophosphateMO AVG report only all year
001Phosphorous, in total orthophosphateMY report only all year
001BOD, 5-day, percent removalMINIMUM >= 85 % all year
001Solids, suspended percent removalMINIMUM >= 85 % all year
001Flow, totalANNL TOT report only Dec
001Flow, totalMO TOTAL report only all year
001Flow, totalANNL TOT report only all year
001Flow, totalANNL TOT report only all year
TRADSolids, total suspendedCUM TOTL report only all year
TRADSolids, total suspendedCUM TOTL report only all year
TRADNitrogen, total [as N]CUM TOTL report only all year
TRADNitrogen, total [as N]CUM TOTL report only all year
TRADPhosphorus, total [as P]CUM TOTL report only all year
TRADPhosphorus, total [as P]CUM TOTL report only all year
TRADFlowYA report only 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