W.R. GRACE & CO. -CONN. GRACE DAVIDSON DIV

NPDES permit IN0000329 · Minor NON-POTW · effective, expires 2026-11-30 · 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
0required values missing, on 0 form(s)
0of 13 forms filed late

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

Reporting

Reports are due about 29 days after each monitoring period ends (read off this permit's own late-day counts in EPA's filings).

Limits in force (30)

OutfallParameterStatisticLimitMonths
003pHDAILY MN >= 6 SU all year
003pHDAILY MX <= 9 SU all year
003Solids, total suspendedMO AVG <= 170 mg/L all year
003Solids, total suspendedDAILY MX <= 254 mg/L all year
003Solids, total suspendedMO AVG <= 600 lb/d all year
003Solids, total suspendedDAILY MX <= 900 lb/d all year
003Sulfate, total [as SO4]MO AVG <= 11024 mg/L all year
003Sulfate, total [as SO4]DAILY MX <= 14698 mg/L all year
003Sulfate, total [as SO4]MO AVG <= 39000 lb/d all year
003Sulfate, total [as SO4]DAILY MX <= 52000 lb/d all year
003Flow, in conduit or thru treatment plantMO AVG report only all year
003Flow, in conduit or thru treatment plantDAILY MX report only all year
003Chlorine, total residualMO AVG <= .0078 mg/L all year
003Chlorine, total residualDAILY MX < .06 mg/L all year
003Chlorine, total residualMO AVG <= .03 lb/d all year
003Chlorine, total residualDAILY MX < .3 lb/d all year
003Toxicity [acute], Ceriodaphnia dubiaMAXIMUM <= 9.4 tox acute Nov
003Toxicity [acute], Ceriodaphnia dubiaMAXIMUM <= 9.4 tox acute Dec
003Toxicity [acute], Ceriodaphnia dubiaMAXIMUM <= 9.4 tox acute Dec
003Solids, total dissolvedMO AVG <= 18938 mg/L all year
003Solids, total dissolvedDAILY MX <= 26570 mg/L all year
003Solids, total dissolvedMO AVG <= 67000 lb/d all year
003Solids, total dissolvedDAILY MX <= 94000 lb/d all year
003Mercury, total recoverableROLL AVG <= 7.8 ng/L Feb, Apr, Jun, Aug, Oct, Dec
003Mercury, total recoverableDAILY MX report only Feb, Apr, Jun, Aug, Oct, Dec
003Chemical Oxygen Demand [COD]MO AVG report only all year
003Chemical Oxygen Demand [COD]DAILY MX report only all year
003Chemical Oxygen Demand [COD]MO AVG report only all year
003Chemical Oxygen Demand [COD]DAILY MX report only all year
003Flow, totalMO TOTAL 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