Biological Wastewater Treatment

Wastewater Treatment Essentials

US Water Pollution Laws

Several Acts designed to protect navigation and human health were passed in late 1800’s – early 1900’s
Early Federal Acts/Amendments in late 1800s – early 1900s
Water Pollution Control Act Amendments1956
Federal Water Pollution Control Act Amendments of 1961
Water Quality Act of 1965
States Required to develop Water Quality Standards, Waste Load Allocations
EPA founded in 1970

NPDES stands for

  • National
  • Pollutant
  • Discharge
  • Elimination
  • System

NPDES is a program for issuing, modifying, revoking and reissuing, terminating, monitoring and enforcing permits and pretreatment standards

  • Scope of the NPDES permit requirement. The NPDES program requires permits for the discharge of “pollutants” from any “point source” into “waters of the United States.” (40 CFR 121.1(b)(1))

What are pollutants?

  • Conventional Pollutants

–(e.g., BOD, TSS, fecal, pH, O&G)

  • Non-Conventional Pollutants

–Neither Toxic nor Conventional (e.g. Chlorine, Ammonia)

  • Toxics & Priority Pollutants

–Toxics:  Initial list of 65 from Toxics Consent Decree

–Priority Pollutants:

  • 126 Pollutants and Classes of Pollutants
  • Includes each compound on Toxics List plus individual compounds (e.g. PCB1242)

What is a point Source?

  • “…any discernible, confined and discrete conveyance, including but not limited to any pipe, ditch, channel, tunnel, conduit, well, discrete fissure, container, rolling stock, concentrated animal feeding operation, or vessel or other floating craft, from which pollutants are or may be discharged. This term does not include agricultural stormwater discharges and return flows from irrigated agriculture.”

What are “Waters of the United States”?

  • Not defined in Clean Water Act
  • Defined in 40 CFR 122.2, but not entirely clear

–Definition controversial for many years

  • Rapanos v. United States & Carabell v. United States
  • Definition of “significant nexus” arguable
  • EP Report Final January 2015 Connectivity of Streams and Wetlands to Downstream Waters: A Review and Synthesis of the Scientific Evidence
  • Final Rule published June 29, 2015

–many legal challenges filed in Courts of Appeals and District Courts

–Nationwide stay of the rule currently in place until Courts system can decide who has jurisdiction

Rule currently not in effect

When do I need a Permit?

  • Before commencement of actual discharge to a water of the state
  • Submit application at least 180 days prior to commencement of discharge or before current permit expiration
  • Submit completed application to permitting authority (i.e., state agency or EPA)
  • Inquire with agency for specific application forms/requirements


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