Mason County Dept of Utilities & Waste Management

NPDES permit WA0038075 · Minor POTW · effective, expires 2029-06-30 · 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
14required values missing, on 11 form(s)
1of 47 forms filed late

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

Reporting

Reports are due about 15 days after each monitoring period ends (read off this permit's own late-day counts in EPA's filings).

Limits in force (32)

OutfallParameterStatisticLimitMonths
001Temperature, water deg. centigradeMO AVG report only (alert) all year
001Temperature, water deg. centigradeWKLY AVG report only (alert) all year
001BOD, 5-day, 20 deg. CMO AVG <= 30 mg/L all year
001BOD, 5-day, 20 deg. CWKLY AVG <= 45 mg/L all year
001BOD, 5-day, 20 deg. CMO AVG <= 13.8 lb/d all year
001BOD, 5-day, 20 deg. CWKLY AVG <= 20.7 lb/d all year
001pHSingle Rdg report only (alert) all year
001Solids, total suspendedMO AVG <= 30 mg/L all year
001Solids, total suspendedWKLY AVG <= 45 mg/L all year
001Solids, total suspendedMO AVG <= 13.8 lb/d all year
001Solids, total suspendedWKLY AVG <= 20.7 lb/d all year
001Nitrogen, ammonia total [as N]MO AVG report only (alert) all year
001BOD, percent removal [total]MO AV MN >= 85 % all year
001EnterococciSingle Rdg report only (alert) all year
001Coliform, fecal generalMO GEOMN <= 117 #/100mL all year
001Coliform, fecal generalWK GEOMN <= 175 #/100mL all year
001FlowMAXIMUM report only (alert) all year
001FlowMO AVG report only (alert) all year
001Solids, suspended percent removalMO AV MN >= 85 % all year
0RFRainfallMAXIMUM report only (alert) all year
0RFRainfallMO AVG report only (alert) all year
CL2Chlorine, total residualAVERAGE <= .5 mg/L all year
CL2Chlorine, total residualWKLY AVG <= .75 mg/L all year
INFBOD, 5-day, 20 deg. CMO AVG report only (alert) all year
INFBOD, 5-day, 20 deg. CWKLY AVG report only (alert) all year
INFBOD, 5-day, 20 deg. CMO AVG report only (alert) all year
INFBOD, 5-day, 20 deg. CWKLY AVG report only (alert) all year
INFSolids, total suspendedMO AVG report only (alert) all year
INFSolids, total suspendedWKLY AVG report only (alert) all year
INFSolids, total suspendedMO AVG report only (alert) all year
INFSolids, total suspendedWKLY AVG report only (alert) all year
INFFlowMO AVG report only (alert) 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