Industrial, municipal, and other point sources of pollution that discharge wastewater directly to surface waters are required to obtain National Pollutant Discharge Elimination System (NPDES) permits. (A point source is a source of pollution that comes from a discrete pipe or other "point".)   NPDES permits limit the amount of pollution that point sources may discharge into surface waters. The purpose of NPDES permits is to protect water quality and public health.

In Idaho, the NPDES permit program is administered by the U.S. Environmental Protection Agency (EPA), which means that EPA is responsible for issuing and enforcing all NPDES permits in Idaho. The state's role in this process is to certify that NPDES-permitted projects comply with state water quality standards.

Idaho is one of only a handful of states where the NPDES program is administered by EPA. States are encouraged by EPA to attain primacy for the program. Primacy enables states to assume responsibility for administering certain federally mandated programs, such as the NPDES program.

In June 2000, a steering committee was formed to consider whether Idaho should seek primacy for the NPDES program. A study was conducted and, in January 2001 and November 2002, reports were issued recommending that Idaho seek primacy for the NPDES program. A majority of steering committee members viewed state primacy as a way to make the program more cost-effective and to streamline the NPDES permitting process.

View NPDES Decision Analysis Reports:

> January 2001 Report (pdf 588 kb, 38 pages)

> November 2002 Report (pdf 2.3 mb, 267 pages)

Legislation to implement the steering committee's recommendations was drafted, but did not garner adequate support for passage during the 2003 legislative session. In August 2004, at the initiative of various industries and interested parties, a work group was chartered by the Environmental Common Sense Committee to reconsider the state primacy issue. The committee considered the pros and cons of shifting responsibility for the NPDES program from EPA to DEQ and, in view of the complexity of this issue, recommended that DEQ more thoroughly review the NPDES primacy issue and develop recommendations as to whether it would be appropriate for Idaho to pursue primacy.

In early 2005, the Idaho Legislature directed DEQ to further explore issues relating to obtaining primacy for the NPDES program. DEQ submitted a summary report of those findings to the Legislature in January 2006.

> View December 2005 Report (pdf 174 kb, 23 pages)     

Wastewater treatment plants collect wastewater (mainly domestic sewage) and may discharge treated wastewater into waters of the Unites States with an NPDES permit. The permits include provisions relating to biosolids; permits for municipal facilities may also specify pretreatment requirements for industries that discharge their wastewater to the wastewater treatment plants. EPA uses the term "publicly owned treatment works" to describe municipal wastewater treatment plants. More.

Biosolids are the nutrient-rich organic materials resulting from the treatment of sewage sludge (the solid, semisolid, or liquid untreated residue generated during the treatment of domestic wastewater [sewage]). Biosolids can be safely recycled and applied as fertilizer.

A biosolids permit is required for wastewater treatment plants that treat domestic sewage and is issued as part of the facility's NPDES permit. Other types of industries may work with biosolids or apply biosolids as fertilizer and may not be required to obtain a biosolids permit (always check with EPA to be sure). However, those who work with biosolids must comply with federal biosolids regulations even when a permit is not required. More.