Water Quality Improvement Projects
Grays Harbor Area


Grays Harbor is an estuarine bay on the southwest coast of Washington State, about 45 miles north of the mouth of the Columbia River. The Chehalis River empties into Grays Harbor near the city of Aberdeen. The significant tributaries to the Chehalis in this watershed resource inventory area (WRIA) include the Satsop, Wynoochee, Wishkah, and Cloquallum River watersheds. The Hoquaim, Humptulips, Elk, and Johns rivers flow directly into Grays Harbor, along with numerous other small watersheds along the northern and southern shores of the harbor.

Grays Harbor is a shallow estuary, with depths averaging less than 20 feet. Much of the western half of the harbor is approved for commercial shellfish harvesting, predominately oysters. The Port of Grays Harbor includes marine terminals for shipping, and is a location for the proposed Imperium-Westway expansion to receive crude oil by rail.

Chehalis River at Montesano, Washington State.  Picture courtesy of Dustin Bilhimer, WA Department of Eologu

Water quality issues


The term “dioxin” refers to a group of chemical compounds sharing certain similar structures and biological characteristics. Dioxin compounds are not created intentionally, but are formed inadvertently by a number of human and natural activities. These activities include combustion and incineration, forest fires, chlorine bleaching of pulp and paper, certain types of chemical manufacturing and processing, and other industrial processes. Dioxins are carcinogens (cancer-causing) and endocrine disruptors. They are persistent in the environment, and can bioaccumulate in animals. More about the hazards of dioxins....

On June 9, 1989, the Washington Department of Ecology (Ecology) listed 8 pulp mills as violating water quality standards for the priority pollutant TCDD, a dioxin. At that time Weyerhaeuser Paper Company (Cosmopolis) and ITT Rayonier (Hoquiam) were discharging to inner Grays Harbor. Their effluent and sludge contained measurable quantities of dioxin.

Ecology developed a total maximum daily load (TMDL) for inner Grays Harbor that set wasteload allocations for two pulp mills that discharged into Grays Harbor. EPA approved the TMDL on June 1992. The ITT Rayonier facility in Hoquiam is now closed, and the Weyerhaeuser Paper Company pulp mill in Cosmopolis has since changed ownership and operation.

No dioxins are allowed to be discharged any longer. Reduction of dioxin in the harbor and sediments are expected to slowly attenuate over time, now that point-sources of dioxin pollution have been removed.

Fecal coliform bacteria

Fecal coliform is a type of “bacteria” common in human and animal waste. It can make people sick and cause the closure of shellfish harvesting beds. Bacteria can get into our waters from untreated or partially treated discharges from wastewater treatment plants, urban stormwater, industrial discharges, improperly functioning septic systems, and from livestock, pets and wildlife.

Grays Harbor and several of its tributaries were listed under section 303(d) of the federal Clean Water Act as not meeting water quality standards for fecal coliform bacteria. Fecal coliform enters the Harbor from a variety of point source dischargers, including the sewage treatment plants in the cities of Aberdeen, Hoquiam, Ocean Shores, and Westport, urban stormwater, and from pulp paper mills.

Shellfish growers in the outer harbor experienced repeated temporary closures due to violations of fecal coliform discharge limits in existing point source permits. Sampling data from the study also indicated that nonpoint sources of fecal coliform may be a concern in tributary watersheds to Grays Harbor. Nonpoint contributions, possibly from onsite septic systems and farm operations, were also found during a shoreline survey conducted by the Washington Department of Health (WDOH) in 1994.

TMDL implementation: getting to clean water


Currently there are no dioxin cleanup sites in Grays Harbor. One of the facilities (ITT Rayonier aka Grays Harbor Paper) which was given a wasteload allocation is no longer operating. The other facility (formerly Weyco and now Cosmo Specialty Fiber) is meeting its wasteload allocation for dioxin. Dioxin is a legacy toxin and expected to attenuate naturally in the harbor.

Fecal coliform bacteria

After Ecology conducted a fecal coliform study in 2000, it developed a total maximum daily load (TMDL) report in 2001. Wasteload and load allocations for fecal coliform bacteria were determined for rivers and creeks draining into Grays Harbor. Ecology submitted the report, which included an implementation strategy, to EPA. EPA approved the TMDL in May 2003.

During public comment on the draft permit for the Weyerhaeuser Cosmopolis Mill permit (mid 2003), new information was presented that led to a revision of the wasteload allocation (WLA) for that facility. The revision is based on the application of studies showing that bacterial fate and transport from the pulp mill are quite different than previously understood. The revised wasteload allocation was incorporated into a new NPDES permit recommendation for the facility. An added public comment process was completed simultaneously for the permit and revised WLA. EPA re-approved the TMDL with the amended WLA in January 2004.

Weyco closed their facility in 2006. It was reopened by Cosmo Specialty Fibers in 2011, and the bacteria wasteload allocation formerly applied to Weyco now applies to Cosmo Specialty Fibers. This re-opened facility has had difficulty meeting their fecal coliform bacteria allocation over the last few years, resulting in temporary closures of commercial shellfish harvest areas in the harbor and could result in a downgrade of classification for areas that are currently approved for commercial shellfish harvest. Cosmo Specialty Fibers is currently working with Ecology and WDOH to address the bacteria pollution issue.

Ecology conducted a study of urban stormwater from Aberdeen, Hoquiam, and Cosmopolis from 2010-2011 to characterize bacteria in stormwater. At 16 urban drain sampling sites, one or both parts of the water quality standards criteria was exceeded. Efforts should be made by all three cities to reduce sources of bacteria to their stormwater systems. The city of Aberdeen will continue to implement the requirements of the Phase II Municipal Stormwater Permit. Cosmopolis and Hoquiam are below the eligibility threshold for obtaining permit coverage, but they should also take action to reduce bacteria pollution sources.

Ecology, the Washington Department of Agriculture (WSDA), and the Grays Harbor Conservation District (GHCD) coordinated responses to address non-point pollution issues resulting from agricultural activities, and continue to use a collaborative approach to provide technical assistance and corrective actions where necessary.

Chehalis River Mouth SR 101 drawbridge, Washington State.  Picture courtesy of Dustin Bilhimer, WA Department of Ecology.

Technical information

TMDL reports are submitted to the U.S. EPA for approval. These documents are also called WQ Improvement Reports (WQIRs). Sometimes the study on which these reports are based is published separately as a TMDL study, or technical report, that describes the results and analysis of the study. The precursor to a study is a Quality Assurance Project Plan (QAPP). The QAPP describes the study design, data collection and data quality objectives. Important follow-up studies to a TMDL are also included in the following table. Unless otherwise specified, the following are Ecology publications.


Document Type Pollutant Title Publication #
TMDL Reports Dioxin

Grays Harbor (Inner) Dioxin Total Maximum Daily Load


Fecal Coliform Bacteria Grays Harbor/Chehalis Watershed Fecal Coliform Bacteria Total Maximum Daily Load Submittal Report 01-10-025
Fecal Coliform Bacteria Amendment to Grays Harbor/Chehalis Watershed Fecal Coliform Bacteria Total Maximum Daily Load Submittal Report 01-10-025amendment
TMDL Implementation Plan

Fecal Coliform Bacteria


Dissolved Oxygen

The Chehalis/Grays Harbor Watershed Dissolved Oxygen, Temperature, and Fecal Coliform Bacteria TMDL: Detailed Implementation (Cleanup) Plan 04-10-065
TMDL Study Fecal Coliform Bacteria Grays Harbor Fecal Coliform Total Maximum Daily Load Study 00-03-020
Follow-up Studies Fecal Coliform Bacteria

Quality Assurance Project Plan: Grays Harbor Fecal Coliform Bacteria Monitoring to Characterize Water Quality in Urban Stormwater Drains


Grays Harbor Fecal Coliform Bacteria Monitoring to Characterize Water Quality in Urban Stormwater Drains 11-10-079



Related information

WRIA 22: Lower Chehalis Watershed Information (Water web site)


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Last updated October 2016


WRIA(s): #22 (Lower Chehalis)
County: Grays Harbor

Water-body Name:
Grays Harbor

Fecal Coliform Bacteria

# of TMDLs:
Dioxin - 1
Fecal Coliform Bacteria - 28

TMDL approved by EPA

Contact Info:
Brett Raunig
Phone: 360-690-4660
Email: Brett.Raunig@ecy.wa.gov

Southwest Region
Department of Ecology
P.O. Box 47775
Olympia, WA 98504 -7775