ONTARIO, CITY OF

NPDES permit OR0020621 · Major POTW · effective, expires 2031-01-31 · EPA's file as of 2026-09-19

Check this month's numbers before you file

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

0values over a limit
2required values missing, on 2 form(s)
4of 18 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 (40)

OutfallParameterStatisticLimitMonths
001Temperature, water deg. centigradeMO AVG report only Jan, Feb, Mar, Apr, Nov, Dec
001Temperature, water deg. centigradeDAILY MX report only Jan, Feb, Mar, Apr, Nov, Dec
001Temperature, water deg. centigradeMX 7D AV report only Jan, Feb, Mar, Apr, Nov, Dec
001BOD, 5-day, 20 deg. CMO AVG <= 30 mg/L Jan, Feb, Mar, Apr, Nov, Dec
001BOD, 5-day, 20 deg. CDAILY MX report only Jan, Feb, Mar, Apr, Nov, Dec
001BOD, 5-day, 20 deg. CMO AVG <= 770 lb/d Jan, Feb, Mar, Apr, Nov, Dec
001BOD, 5-day, 20 deg. CDAILY MX <= 1500 lb/d Jan, Feb, Mar, Apr, Nov, Dec
001BOD, 5-day, 20 deg. CMO AVG report only all year
001BOD, 5-day, 20 deg. CMX WK AV <= 45 mg/L Jan, Feb, Mar, Apr, Nov, Dec
001BOD, 5-day, 20 deg. CMX WK AV <= 1100 lb/d Jan, Feb, Mar, Apr, Nov, Dec
001pHDAILY MN >= 6 SU Jan, Feb, Mar, Apr, Nov, Dec
001pHDAILY MX <= 9 SU Jan, Feb, Mar, Apr, Nov, Dec
001pHMO MIN report only all year
001pHMO MAX report only all year
001Solids, total suspendedMO AVG <= 85 mg/L Jan, Feb, Mar, Apr, Nov, Dec
001Solids, total suspendedDAILY MX report only Jan, Feb, Mar, Apr, Nov, Dec
001Solids, total suspendedMO AVG <= 2200 lb/d Jan, Feb, Mar, Apr, Nov, Dec
001Solids, total suspendedDAILY MX <= 4300 lb/d Jan, Feb, Mar, Apr, Nov, Dec
001Solids, total suspendedMO AVG report only all year
001Solids, total suspendedMX WK AV <= 130 mg/L Jan, Feb, Mar, Apr, Nov, Dec
001Solids, total suspendedMX WK AV <= 3300 lb/d Jan, Feb, Mar, Apr, Nov, Dec
001Nitrogen, ammonia total [as N]MO MAX report only Jan, Feb, Mar, Apr, Nov, Dec
001Nitrogen, ammonia total [as N]MO MAX report only Jan, Feb, Mar, Apr, Nov, Dec
001Arsenic, total recoverableMO AVG report only Jan, Feb, Mar, Apr, Nov, Dec
001Arsenic, total recoverableDAILY MX report only Jan, Feb, Mar, Apr, Nov, Dec
001Arsenic, InorganicMO MAX report only Jan, Feb, Mar, Apr, Nov, Dec
001Flow, in conduit or thru treatment plantMO AVG report only Jan, Feb, Mar, Apr, Nov, Dec
001Flow, in conduit or thru treatment plantDAILY MX report only Jan, Feb, Mar, Apr, Nov, Dec
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 residualMO AVG <= .05 mg/L Jan, Feb, Mar, Apr, Nov, Dec
001Chlorine, total residualDAILY MX <= .05 mg/L Jan, Feb, Mar, Apr, Nov, Dec
001E. coliMO GEO <= 126 #/100mL Jan, Feb, Mar, Apr, Nov, Dec
001E. coliDAILY MX <= 406 #/100mL Jan, Feb, Mar, Apr, Nov, Dec
001E. coliMO GEO <= 126 #/100mL Jan, Feb, Mar, Apr, Nov, Dec
001E. coliDAILY MX report only Jan, Feb, Mar, Apr, Nov, Dec
001Flow, totalDAILY MX <= 0 gal May, Jun, Jul, Aug, Sep, Oct
001BOD, 5-day, percent removalMO AV MN >= 85 % Jan, Feb, Mar, Apr, Nov, Dec
001Solids, suspended percent removalMO AV MN >= 65 % Jan, Feb, Mar, Apr, Nov, Dec
001Chlorine usageMO AVG report only Jan, Feb, Mar, Apr, Nov, Dec

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