This section describes water quality problems in the Chehalis River Basin derived from existing water quality information and data from agencies and water quality experts.
In accordance with the guidelines of the Nonpoint Rule, Chapter 400-12 Washington Administrative Code (WAC), this section describes the extent of beneficial use support of the basin's waterbodies and/or stream segments, and whether the waterbodies are impaired or threatened by nonpoint and point source pollution. If so, the extent of the impairment or threat is listed. Existing water quality conditions are compared to State and Federal water quality standards, and wetlands affected or threatened by nonpoint source pollution are described.
An unofficial survey of Chehalis River Basin residents and members of the Chehalis River Council was conducted in Summer 1991 to sample residents' perceptions of water quality problems and polluted areas in the basin. A full description of the survey and its results are presented later in this document.
Chapter 173-201 WAC, Water Quality Standards for Surface Waters of the State of Washington, established water quality standards for surface water consistent with public health, public enjoyment of these waters, and propagation and protection of fish, shellfish, and wildlife. All surface waters in the state are classified according to their characteristic (beneficial) uses and water quality conditions. If waterbodies do not meet their designated water quality standards, or do not supply a full range of characteristic beneficial uses, then the waterbodies are classified as "water quality limited" or "impaired".
State water quality standards Table 1a designate most of the waterbodies of the Chehalis River Basin as Class ATable 1b. The upper reaches of the mainstem Chehalis, Wynoochee, Satsop, Wishkah, Humptulips and Skookumchuck rivers are Class AA. The lower stretches of the Hoquiam River and Wishkah River, and the inner estuary of Grays Harbor are designated as Class B waters. There are no Class C waters in the Chehalis River Basin.
The beneficial uses of Class A and AA waters are identical and include water supply, fish spawning and rearing, wildlife habitat, recreation, and navigation. Class B waters do not support uses for domestic drinking water, salmonid spawning, or primary contact recreation, and support only limited fishing. The water quality criteria established to protect beneficial uses are the most restrictive for AA waters, and progressively less restrictive for lower waterbody classifications. The water quality standards also identify three special conditions which relax the dissolved oxygen criterion for specified Chehalis River Basin waterbodies: the mainstem Chehalis near Centralia/Chehalis (5.0 mg/L, June 1 - September 15), Inner Grays Harbor (5.0 mg/L, year-round), and Hanaford Creek, a tributary of the Skookumchuck River (6.5 mg/L, year-round).
The Chehalis River Basin and Grays Harbor have experienced long-standing water quality problems and impairment of beneficial uses. Locations, causes, and sources of impairment in the basin are listed in Table 3. There are waterbodies in the Chehalis River Basin which may be impaired, but are not listed in Table 3. due to a lack of long-term monitoring or evaluation. Only 14% of the total stream miles in Washington have been assessed for beneficial use support (DOE, 1989b). Table 3. was compiled from the Waterbody System, which was developed by the Environmental Protection Agency and adopted for use by the Washington Department of Ecology to assist in managing surface water data for Clean Water Act water quality assessments.
The purpose of Ecology's assessment process is to determine whether waterbodies support the goals of the Clean Water Act and attain state water quality standards. Available information on water quality status, trends, and beneficial use support were collected and analyzed for each designated waterbody to determine the extent to which it meets Clean Water Act goals and state water quality standards. The causes and sources of beneficial use impairments were also determined from available information (DOE, 1989b).
Department of Ecology staff used existing reports and personal communications with water quality experts across the state to compile the Waterbody System and assess waterbodies. The Waterbody System has some limitations, both in its design and in the data which has been included in the database. In some cases, these limitations may affect the results which are presented in this plan. The Waterbody System, nevertheless, represents the most comprehensive effort to date to assemble available water quality data for the State of Washington and to systematically analyze it. The Department of Ecology is working with the Environmental Protection Agency to address some of the Waterbody System design limitations and will be working to improve the database.
To ensure accuracy of assessments, and to verify causes and sources of impairment, water quality monitoring programs should be expanded in the Chehalis River Basin. Table 4a and Table 4b show which impaired waterbodies in the basin were assessed on an "evaluated" basis, and which were assessed on a "monitored" basis. Waterbodies assessed on an "evaluated" basis probably should be monitored more extensively. For the Chehalis River Council's recommendations for expanded monitoring, see the "Water Quality Monitoring Plan" in the Technical Report supplement to this plan.
Unfortunately, as the costs of water quality monitoring in the Chehalis Basin have risen, funding for long-term monitoring has remained static. This has caused the Department of Ecology to discontinue long-term monitoring at the Mellen Street station in the Chehalis-Centralia reach (river mile [RM] 66-76). (Note: river mile (RM) refers to the distance from the mouth, or entry point of the river). Ecology has been conducting extensive water quality monitoring in 1991-1992 related to the Total Maximum Daily Load project in the upper Chehalis River Basin, but intensive, short-term monitoring cannot replace the value of long-term monitoring. The establishment and continuation of a long-term water quality database allows the opportunity to determine water quality trends over time. Without this long-term database, the effectiveness of water pollution control programs, such as those outlined in this plan, are more difficult to ascertain.
The Chehalis-Centralia reach has been the site of chronic low dissolved oxygen in late summer and fall (Joy, 1984); Grays Harbor has a history of severely degraded water quality and recurrent fish kills dating back to the 1930's (Seiler, 1989); and fish kills and blockages of anadromous species have plagued other reaches. Department of Ecology personnel also cite problems with ammonia, turbidity, fecal bacteria, and nutrient/algal growth (Pickett, 1992).
In August 1989, the Black and Chehalis Rivers suffered a massive juvenile fish kill of over 100,000 fish, plus over 300 adult Chinook salmon in the Chehalis River. The Department of Ecology concluded in the Black River Fish Kill Report, that "...the fish kill was caused by a pollutant(s) discharged to the (Black) river resulting in an acute mortality,..." and that "...although the ambient water quality in the Black and Chehalis River was not ideal for salmon, trout, and whitefish in early August 1989, this fish kill event was not caused by ambient river conditions." The investigation of the August 1989 fish kill revealed that chronic water quality problems associated with elevated levels of nutrients exist in the lower Black River (DOE, 1989a).
The report also states, "...the Chehalis River from the City of Chehalis to the Satsop River (tidal influence point)...has a history of fish kills associated with high temperatures and low dissolved oxygen..."
Four Chehalis River mainstem segments are listed in the Washington State 1990 305(b) Report as "water quality limited" (WQL) based on "monitored" assessments, as are Salzer Creek (RM 69.2) and Dillenbaugh Creek (RM 74.4) Table 4a. Two segments of the Wynoochee River (RM 13.0) as well as several segments of the Newaukum River (RM 75.2) are included on the WQL list based on "evaluated" assessments Table 4b).
Assessments were prepared on either a "monitored" or an "evaluated" basis. Where site specific sampling data from the last five years was available, assessments were made on a monitored basis. Evaluated assessments are based on historical water quality monitoring data (monitoring conducted more than five years ago), sampling data that did not meet the minimum criteria for monitored assessments, knowledge of pollution sources, and other indirect or historic evidence (DOE, 1992b).
Waterbodies are considered to be "water quality limited", or impaired if they are not expected to fully support designated beneficial uses and the Clean Water Act's fishable and swimmable goals after the application of technology-based treatment requirements. The primary causes of impaired surface waters in the basin (Table 3 are bacteria, temperature problems, dissolved oxygen problems, siltation and suspended sediments. Other causes of impairment cited for the basin are nutrients, metals, pentachlorophenol, chlorine, and unknown causes (DOE, 1992b).
Water quality data from the six freshwater stations shown in Table 5a.were analyzed for water quality violations during 1978-1991 (Aroner, 1991). It should be noted that station 23A120 at Centralia has been discontinued by the Department of Ecology. Other historical water quality monitoring sites in the Chehalis River Basin are listed in Table 5b.
The temperature standard was routinely exceeded in the June 1 to September 15 time period, particularly at the Centralia station. Temperature measurements at the Satsop River station were always below the maximum temperature standard.
Dissolved oxygen violations were recorded at the Centralia, Porter, Montesano, and Satsop stations. At Centralia, most violations were recorded during the "special condition" period of relaxed dissolved oxygen standards (5.0 mg/L from June 1 to September 15). Two extreme measurements of 3.5 and 3.0 were recorded on July 25, 1989 at 186 cfs and on October 8, 1979, at 121 cfs, respectively. Critical low flows are defined by the seven-day low flow which recurs once every ten years on the average (7Q10). An approximate 7Q10 for this reach would be 90 cfs. Low flow periods usually occur in the late summer or early fall. All dissolved oxygen excursions for the Porter, Montesano, and the Satsop stations (5 total), were in the summer season.
On October 8, 1991, Department of Ecology, Ambient Monitoring Section personnel detected an extensive volume of oxygen-devoid water moving down the Chehalis River below the mouth of the Newaukum River (RM 75.2). Preliminary results indicated dissolved oxygen levels of 0.0-0.5 mg/L throughout the water column.
There were several pH excursions at the 6 freshwater stations.
There was only one excursion of ammonia toxicity criteria (on the Satsop River). The excursion was due to a high instream total ammonia, not high pH or temperature, and is either a statistical outlier, or the result of a spill or unauthorized discharge.
For both the Montesano and Centralia stations, the fecal bacteria standard was violated almost every year. Dryad and Porter have fewer years with an excursion. The geometric mean was exceeded infrequently at Montesano and Centralia based on calendar years. Based on a 1-year moving-average window, most excursions occurred at Montesano, from 1986 on. The Centralia station experienced a few excursions in the 1979-1991 time frame. Sampling at Porter for fecal coliforms apparently did not commence until 1982.
Alternatively, a 4-month moving-average window was computed for all sites (Aroner, 1991). This actually conforms better to the seasonality with which primary contact recreation would be expected (i.e., swimming, boating) and also reflects the seasonality of the bacteria. With this computational approach it is seen that the frequency of excursions rises at all mainstem sites. Excursions are almost annual as measured at the Centralia and Montesano station.
A total phosphate-phosphorus of 100µg/L was selected by Aroner as the criterion to apply to the Chehalis Basin. This value is usually applied to standing waters, so its application here for flowing waters is conservative (a 100µg/L observation is of less concern in flowing waters). The Centralia (Mellen Street) site had by far the most excursions, with Porter and Montesano next highest but well below Centralia. An interesting feature is that at the Dryad, Porter, Montesano, and Satsop River stations most or all of the excursions were in the wet winter months, whereas at the Centralia station three times as many excursions were observed in the June-September period as in the remaining months. This suggests that point sources of phosphorus (with a dilution mechanism) dominate the Chehalis-Centralia reach while nonpoint sources dominate but at a much lesser magnitude in the other reaches. It should be noted that the Centralia monitoring station is located on the Mellen Street bridge upstream of the Centralia waste water treatment plant.
Ground water quality data for the Chehalis River Basin are scarce. However, specific ground water problem areas have been identified throughout the basin due to contamination from various waste management practices including improperly operated or designed septic systems, landfills, storm drains, leaking underground storage tanks, improper handling of toxic substances, leaking drums, impoundment, pesticide disposal, spills, and drug labs. The Department of Ecology Affected Media and Contaminants Report lists 37 sites in the Chehalis River Basin as contaminated by a variety of pollutants. Twenty-seven of the sites are listed as sources of actual or potential ground water contamination (DOE, 1992a). One major threat to surface and ground water supplies is the large number of leaking underground storage tanks. An estimated 5-9% of all tanks throughout the state are leaking. Forty percent of all tanks are more than 15 years old. Nearly 80% are bare steel with no corrosion protection. One quarter of all tanks statewide are not monitored to detect leaks, while 42% use only daily inventory records for this purpose.
Ground water problem areas in the Chehalis River Basin have been identified by county and state health departments. Lewis County: Ford's Prairie, Waunch Prairie, Coal Creek, Salzer Valley, South Chehalis, Skookumchuck Valley, and Coffee Creek. Thurston County: Bucoda/Tenino area, Rochester, Grand Mound, Scott Lake, Scatter Creek, and Maple Lane Correctional Facility. Mason County: Simpson Lake and Lake Nahwatzel. Grays Harbor County: Central Park, Bench Drive in Aberdeen, Ocean Shores, Endresen Road in Hoquiam, Lake Sylvia in Montesano, Westport, Strawberry Hill in Elma, Highland Drive in Cosmopolis, and the Grayland area (Morris, 1988; Beck, 1975; Stevens, et al. 1974). The most common causes of contamination listed were failing septic systems, wood waste, solvents, agricultural waste (manure and pesticides), automotive waste, mining spoils, landfills, polychlorinated biphenyls, and industrial waste (DOE, 1992b).
Due to varying definitions of wetlands, the extent of wetlands in the Chehalis River Basin is unknown, yet if defined as those areas with hydric or "wet" soils (U.S. Department of Agriculture - Soil Conservation Service, 1975), these areas of wet soils make up approximately 16.9% of the basin. Most of these wet areas lie in the valleys, with a smaller number of forested wetlands in the basin's uplands.
An informal water quality survey was conducted at the Southwest Washington Fair in August 1991, and with the members of the Chehalis River Council at their August and September 1991 meetings. The survey asked: (1) "What do you feel are the worst water quality problem(s) in the Chehalis River Basin?"; and (2) "In which area(s) of the Chehalis River Basin do these water quality problem(s) exist?" This survey was conducted merely to sample resident perceptions and to raise public awareness, not as a statistically valid indication of water quality problems. Nearly 100 responses were received at the Fair, with an additional 50 responses from members of the Chehalis River Council. The leading areas of concern were agriculture (including livestock handling and farming practices), the pulp mills in Grays Harbor, logging, failing septic systems, and industry.
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