Liberte Environmental Associates

NPDES Permits Potentially Affecting Water Quality


Final NPDES Wastewater Permits - Issued by Oregon Department of Environmental Quality

This list consists of permit documents* (see end) made available by Oregon DEQ and is not all inclusive. All documents are PDF except where indicated.

Pacific City Sewage Treatment Plant (STP): Final NPDES Wastewater Permit Related Documents

Pacific City STP - Final Permit. This document is also provided as permit in html format*.

Pacific City STP Final Fact Sheet and Reasonable Potential Analysis (RPA). This document is also provided as fact sheet in html format*.

Permitted Mixing Zone Size for Toxicity:
Waterbody: Nestucca River at about River Mile (RM) 1.5. Discharge located in tidal estuary affected by the Pacific Ocean.
Acute Mixing Zone: 10-foot radius about a 36-foot long diffuser. See Fact Sheet.
Acute Mixing Zone Surface Area: Estimated SA is 1,034 square feet.
Acute Mixing Zone Volume: DEQ fact sheet shows a minimum depth of about 8 ft above the diffuser so the Acute MZ volume is approximately 8,273.3 cubic feet (i.e., 61,884 gallons).
Chronic Mixing Zone: 100-foot radius about a 36-foot long diffuser.
Chronic Mixing Zone Surface Area: Estimated SA is 38,616 square feet.
Chronic Mixing Zone Volume: DEQ fact sheet shows a minimum depth of about 8 ft above the diffuser so the Chronic MZ volume is approximately 308,927 cubic feet (i.e., 2.3 million gallons).

Pacific City STP, Oregon: Draft NPDES Wastewater Permit Related Documents. The DEQ comment period for this proposed NPDES Wastewater Permit Renewal ended on September 23, 2011.

Pacific City Sewage Treatment Plant Public Notice

Pacific City Sewage Treatment Plant Draft NPDES Permit

Pacific City STP previous permit expired on September 30, 2011.

Pacific City STP - Previous 2006 Permit*

Pacific City STP - Previous 2006 Fact Sheet

*LEA Disclaimer for compiled, unlocked, OCR and converted html process documents: From time to time LEA will post on this website scanned documents, and additional documents otherwise limited in accessibility. Accordingly, LEA may use document unlocking, optical character recognition (OCR) and html conversion capabilities to provide accessible, tagged text documents for use by people with visual impairments, and also provide searchable documents. The unlocking, OCR and html conversion processes are not faultless, and hence LEA cannot guarantee document perfection. However, taking these caveats into account, document accessibility is greatly increased. LEA also posts the original document where necessary, as obtained by LEA, such that users may compare any potential imperfections in the unlocked, OCR, html conversion and other documents.