National Oilwell Varco, LP — NPDES permit TX0062642: limits, due date and EPA's record

Oil And Gas Field Machinery, Houston, Texas. NPDES permit TX0062642, in force until May 26, 2027. Last 12 months: over a limit once (last April 2026), 1 of 18 reports late. Source: EPA ECHO, Oct 22, 2026.

Last 12 months (Oct 1, 2025 – Sep 30, 2026)

Period ending	Parameter	Reported	Limit	Over by
April 2026	Copper, total [as Cu], daily average	.0327 mg/L	≤ .016 mg/L	104%

Limits in force (56)

Parameter	Statistic	Limit	Months
Oxygen, dissolved [DO]	monthly minimum	≥ 4 mg/L	Jan, Feb, Mar, Nov, Dec
Oxygen, dissolved [DO]	monthly minimum	≥ 6 mg/L	Apr–Oct
pH	minimum	≥ 6 SU	all year
pH	maximum	≤ 9 SU	all year
Solids, total suspended	daily average	≤ 7.73 lb/d	all year
Solids, total suspended	daily maximum	≤ 18.5 lb/d	all year
Oil & Grease	daily average	≤ 10 mg/L	all year
Oil & Grease	daily maximum	≤ 15 mg/L	all year
Oil & Grease	daily average	≤ 4.2 lb/d	all year
Oil & Grease	daily maximum	≤ 6.2 lb/d	all year
Nitrogen, ammonia total [as N]	daily average	≤ .83 lb/d	Apr–Oct
Nitrogen, ammonia total [as N]	daily average	≤ 1.25 lb/d	Jan, Feb, Mar, Nov, Dec
Nitrogen, ammonia total [as N]	daily maximum	≤ 2.5 lb/d	Apr–Oct
Nitrogen, ammonia total [as N]	daily maximum	≤ 3.75 lb/d	Jan, Feb, Mar, Nov, Dec
Cyanide, free [amenable to chlorination]	daily average	≤ .038 mg/L	all year
Cyanide, free [amenable to chlorination]	daily maximum	≤ .082 mg/L	all year
Cyanide, free [amenable to chlorination]	daily average	≤ .013 lb/d	all year
Cyanide, free [amenable to chlorination]	daily maximum	≤ .028 lb/d	all year
Cadmium, total [as Cd]	daily average	≤ .011 mg/L	all year
Cadmium, total [as Cd]	daily maximum	≤ .024 mg/L	all year
Cadmium, total [as Cd]	daily average	≤ .004 lb/d	all year
Cadmium, total [as Cd]	daily maximum	≤ .009 lb/d	all year
Chromium, total [as Cr]	daily average	≤ .342 mg/L	all year
Chromium, total [as Cr]	daily maximum	≤ .554 mg/L	all year
Chromium, total [as Cr]	daily average	≤ .142 lb/d	all year
Chromium, total [as Cr]	daily maximum	≤ .231 lb/d	all year
Copper, total [as Cu]	daily average	≤ .016 mg/L	all year
Copper, total [as Cu]	daily maximum	≤ .034 mg/L	all year
Copper, total [as Cu]	daily average	≤ .006 lb/d	all year
Copper, total [as Cu]	daily maximum	≤ .013 lb/d	all year
Lead, total [as Pb]	daily average	≤ .086 mg/L	all year
Lead, total [as Pb]	daily maximum	≤ .138 mg/L	all year
Lead, total [as Pb]	daily average	≤ .036 lb/d	all year
Lead, total [as Pb]	daily maximum	≤ .058 lb/d	all year
Nickel, total [as Ni]	daily average	≤ .116 mg/L	all year
Nickel, total [as Ni]	daily maximum	≤ .245 mg/L	all year
Nickel, total [as Ni]	daily average	≤ .048 lb/d	all year
Nickel, total [as Ni]	daily maximum	≤ .102 lb/d	all year
Silver, total [as Ag]	daily average	≤ .012 mg/L	all year
Silver, total [as Ag]	daily maximum	≤ .025 mg/L	all year
Silver, total [as Ag]	daily average	≤ .005 lb/d	all year
Silver, total [as Ag]	daily maximum	≤ .01 lb/d	all year
Zinc, total [as Zn]	daily average	≤ .179 mg/L	all year
Zinc, total [as Zn]	daily maximum	≤ .379 mg/L	all year
Zinc, total [as Zn]	daily average	≤ .075 lb/d	all year
Zinc, total [as Zn]	daily maximum	≤ .158 lb/d	all year
Flow, in conduit or thru treatment plant	daily average	≤ .05 MGD	all year
Flow, in conduit or thru treatment plant	daily maximum	≤ .13 MGD	all year
Chlorine, total residual	monthly minimum	≥ 1 mg/L	all year
Chlorine, total residual	monthly maximum	≤ 4 mg/L	all year
E. coli	daily average	≤ 63 CFU/100mL	all year
E. coli	daily maximum	≤ 197 CFU/100mL	all year
Total toxic organics [TTO] [40 CFR433]	daily maximum	≤ 2.13 mg/L	all year
Total toxic organics [TTO] [40 CFR433]	daily maximum	≤ .196 lb/d	all year
BOD, carbonaceous [5 day, 20 C]	daily average	≤ 4.17 lb/d	all year
BOD, carbonaceous [5 day, 20 C]	daily maximum	≤ 12.51 lb/d	all year

How strict are these limits?

Your permit document is the final word. As JSON: /api/v1/permits/TX0062642 · MCP: https://passage-data.com/mcp