TENARIS AMBRIDGE

NPDES ID: PA0006335

X — SNC: Effluent violation (non-monthly average limit)

The facility discharged more of a pollutant than its permit allows, measured over a period other than a monthly average.

This quarter: 12 reporting violations.

Mentions

Tenaris Ambridge misses its oil and grease limit for a third straight quarter

On the Ohio River in Beaver County, Tenaris Ambridge, a steel pipe manufacturing plant, has now exceeded its permitted oil and grease discharge limit for three consecutive reporting periods: 73% over at the end of last December, 110% over at the end of March, and 71% over in the report filed earlier this month. That sustained pattern of measured effluent exceedances, not a paperwork lapse, is what has landed the facility in significant non-compliance with its federal discharge permit. Oil and grease limits exist for a concrete reason: the petroleum-based coating and cutting fluids used in pipe manufacturing can spread into surface films that block oxygen exchange at the water's surface, and coat sediment and gill tissue if they reach the river in volume. Fish and macroinvertebrates in a stretch that receives repeated slugs of this material can see reduced respiratory efficiency over time even without a single dramatic spill. Current USGS readings on the Ohio near Ambridge, at the Montgomery, Emsworth, and Sewickley gauges, show dissolved oxygen, pH, and temperature all within normal range for this stretch, and the EPA lists no impaired waters within ten miles. There is no measured downstream effect tied to this exceedance yet. What the record does show plainly is a facility that has missed its own permitted limit three reporting periods running, on a stretch of river the Sewickley Valley Conservation Association works downstream of Ambridge. A pattern this consistent is worth watching closely as future quarterly reports come in.

Keep reading

Violations

April 30, 2026

Oil & Grease

71% over limit

Discharged 17.1 mg/L against a permitted limit of 10 mg/L (DAILY MX)

DMR, Limited - Numeric Violation

March 31, 2026

Oil & Grease

32% over limit

Discharged 13.2 mg/L against a permitted limit of 10 mg/L (DAILY MX)

DMR, Limited - Numeric Violation

February 28, 2026

Oil & Grease

110% over limit

Discharged 21 mg/L against a permitted limit of 10 mg/L (DAILY MX)

DMR, Limited - Numeric Violation

December 31, 2025

Oil & Grease

73% over limit

Discharged 17.3 mg/L against a permitted limit of 10 mg/L (DAILY MX)

DMR, Limited - Numeric Violation

First flagged

April 14, 2026 (6 months ago)

Last confirmed

October 15, 2026 (7 days ago)