NATIONAL OILWELL VARCO, LP

NPDES permit TX0062642 · Minor NON-POTW · effective, expires 2027-05-26 · EPA's file as of 2026-09-19

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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

1values over a limit
0required values missing, on 0 form(s)
1of 17 forms filed late

Last period with anything received: 2026-07-31. Most often over: Copper, total [as Cu] (1).

Reporting

Reports are due about 20 days after each monitoring period ends (read off this permit's own late-day counts in EPA's filings).

Limits in force (56)

OutfallParameterStatisticLimitMonths
001Oxygen, dissolved [DO]MO MIN >= 4 mg/L Jan, Feb, Mar, Nov, Dec
001Oxygen, dissolved [DO]MO MIN >= 6 mg/L Apr, May, Jun, Jul, Aug, Sep, Oct
001pHMINIMUM >= 6 SU all year
001pHMAXIMUM <= 9 SU all year
001Solids, total suspendedDAILY AV <= 7.73 lb/d all year
001Solids, total suspendedDAILY MX <= 18.5 lb/d all year
001Oil & GreaseDAILY AV <= 10 mg/L all year
001Oil & GreaseDAILY MX <= 15 mg/L all year
001Oil & GreaseDAILY AV <= 4.2 lb/d all year
001Oil & GreaseDAILY MX <= 6.2 lb/d all year
001Nitrogen, ammonia total [as N]DAILY AV <= .83 lb/d Apr, May, Jun, Jul, Aug, Sep, Oct
001Nitrogen, ammonia total [as N]DAILY AV <= 1.25 lb/d Jan, Feb, Mar, Nov, Dec
001Nitrogen, ammonia total [as N]DAILY MX <= 2.5 lb/d Apr, May, Jun, Jul, Aug, Sep, Oct
001Nitrogen, ammonia total [as N]DAILY MX <= 3.75 lb/d Jan, Feb, Mar, Nov, Dec
001Cyanide, free [amenable to chlorination]DAILY AV <= .038 mg/L all year
001Cyanide, free [amenable to chlorination]DAILY MX <= .082 mg/L all year
001Cyanide, free [amenable to chlorination]DAILY AV <= .013 lb/d all year
001Cyanide, free [amenable to chlorination]DAILY MX <= .028 lb/d all year
001Cadmium, total [as Cd]DAILY AV <= .011 mg/L all year
001Cadmium, total [as Cd]DAILY MX <= .024 mg/L all year
001Cadmium, total [as Cd]DAILY AV <= .004 lb/d all year
001Cadmium, total [as Cd]DAILY MX <= .009 lb/d all year
001Chromium, total [as Cr]DAILY AV <= .342 mg/L all year
001Chromium, total [as Cr]DAILY MX <= .554 mg/L all year
001Chromium, total [as Cr]DAILY AV <= .142 lb/d all year
001Chromium, total [as Cr]DAILY MX <= .231 lb/d all year
001Copper, total [as Cu]DAILY AV <= .016 mg/L all year
001Copper, total [as Cu]DAILY MX <= .034 mg/L all year
001Copper, total [as Cu]DAILY AV <= .006 lb/d all year
001Copper, total [as Cu]DAILY MX <= .013 lb/d all year
001Lead, total [as Pb]DAILY AV <= .086 mg/L all year
001Lead, total [as Pb]DAILY MX <= .138 mg/L all year
001Lead, total [as Pb]DAILY AV <= .036 lb/d all year
001Lead, total [as Pb]DAILY MX <= .058 lb/d all year
001Nickel, total [as Ni]DAILY AV <= .116 mg/L all year
001Nickel, total [as Ni]DAILY MX <= .245 mg/L all year
001Nickel, total [as Ni]DAILY AV <= .048 lb/d all year
001Nickel, total [as Ni]DAILY MX <= .102 lb/d all year
001Silver, total [as Ag]DAILY AV <= .012 mg/L all year
001Silver, total [as Ag]DAILY MX <= .025 mg/L all year
001Silver, total [as Ag]DAILY AV <= .005 lb/d all year
001Silver, total [as Ag]DAILY MX <= .01 lb/d all year
001Zinc, total [as Zn]DAILY AV <= .179 mg/L all year
001Zinc, total [as Zn]DAILY MX <= .379 mg/L all year
001Zinc, total [as Zn]DAILY AV <= .075 lb/d all year
001Zinc, total [as Zn]DAILY MX <= .158 lb/d all year
001Flow, in conduit or thru treatment plantDAILY AV <= .05 MGD all year
001Flow, in conduit or thru treatment plantDAILY MX <= .13 MGD all year
001Chlorine, total residualMO MIN >= 1 mg/L all year
001Chlorine, total residualMO MAX <= 4 mg/L all year
001E. coliDAILY AV <= 63 CFU/100mL all year
001E. coliDAILY MX <= 197 CFU/100mL all year
001Total toxic organics [TTO] [40 CFR433]DAILY MX <= 2.13 mg/L all year
001Total toxic organics [TTO] [40 CFR433]DAILY MX <= .196 lb/d all year
001BOD, carbonaceous [5 day, 20 C]DAILY AV <= 4.17 lb/d all year
001BOD, carbonaceous [5 day, 20 C]DAILY MX <= 12.51 lb/d 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