A Report on the Health of Surface Water in Pierce County

Surface Water Health 2010 Report Card A report on the health of surface water in Pierce County

CONTENTS What is the Surface Water Health Report Card? 4 How is Stream Health Monitored? 5 How are the Measurements Used? 5 What do the Grades Mean? 6 Water Year 2010 Results 6 Probable Contaminants and Sources 7 How can you help? 7 Pierce County Watersheds Map 8 - 9 Stream Report Cards by Watershed 10 - 17 Monitored Lakes Report Card 18 - 19 Appendix A- Determining Stream Grades 20 Appendix B- Methodology & Water Quality Index 21 - 22 Appendix C- Benthic Index of Biotic Integrity 23 Appendix D- Section 303 (d) list 24 Appendix E- Stream Data Summary & 25 Grade Assignment Appendix F- More Information on Lake Grades 26 - 27 Appendix G- Lake Data Summary & 28 - 29 Grade Assignment Appendix H- Lake Report Card Factors 30 - 31

Prepared by:

Pierce County Public Works & Utilities Surface Water Management Division Water Quality and Watershed Section www.piercecountywa.org/wqws Surface Water Health Report Card

Monitored Streams Grades Name 2009 2010 Artondale C C- i Canyon B B Canyon Falls C C+ h Clear D+ C- h Clover D D+ h Crescent C+ C i Diru C+ C+ Dutcher C B- h Fennel B- B- Goodnough D+ C- h Horn C C- i Kapowsin C+ C+ Lacamas C- C+ h Spanaway Creek Lynch C+ B h Mark Dickson C C What is the Surface Water Health Report Card? McCormick C- C- The Pierce County Surface Water Health Report Card provides a Minter C- C h system for rating and grading the health of Pierce County streams. Nelyaly C- C h Our first report card was issued in 2008, and it described the baseline Ohop C C+ h conditions for 32 streams located throughout the County. This report Purdy C C is based on sampling done in the 2010 water year. It describes 2010 Ray Nash C- C- monitoring results for 30 of those streams. Rody C C+ h Rosedale C C+ h The Surface Water Management Division uses multiple assessment Spanaway N/A C- methods to monitor surface water health over time. Monitoring Spiketon N/A C helps us gather information on the health of area waters, and helps Squally C B- h us identify where to focus resources and improvement efforts. The Swan C- D+ i report card serves to increase public understanding and involvement Tanwax C+ C i in protecting and improving water quality. Voight C B- h Wilkeson C+ C i Data and associated grades can vary significantly from year to year, so collecting data over a long period is important. As we collect data h Improved over time, we will be better able to analyze trends and measure our i Decreased progress. Same N/A Not enough data available to This year’s report card includes water quality information about six determine a grade this year freshwater lakes in the county. This information starts on page 18. For more detailed information see Appendix E

Pg. 4 How is stream health monitored? Pierce County monitors stream health using a watershed approach. A watershed is the geographic region that drains water (and everything water carries) into a river, stream, lake, or Puget Sound. Watersheds are defined by natural features like mountains and valleys, and not by political boundaries. Since all land within a watershed drains to a common outlet, every activity within the watershed could be a source of pollution and could affect the overall watershed health. Water pollution that has no single, identifiable source is known as “nonpoint source pollution.”

Pierce County is divided into five main watersheds (see map on pages 8-9). The largest watershed monitored in the county is the Puyallup River Watershed, which drains an area of about 1,052 square miles. The smallest watershed monitored is the Chambers-Clover Creek Watershed, which drains an urban area about 149 square miles in size. The Key Peninsula, Gig Harbor, and surrounding islands are grouped into one watershed for monitoring purposes. The Nisqually River Watershed extends from Mt. Rainier to the Nisqually River Delta on Puget Sound. Each watershed contains a number of freshwater streams, which are the focus of our current monitoring efforts.

Water samples are collected monthly provided sufficient flow is present. The samples are collected from monitoring stations set up at each stream. Water samples are analyzed for nine water quality parameters. Some are measured directly in the field when the samples are collected, and others are sent to a laboratory for analysis. Samples are measured for fecal coliform bacteria, dissolved oxygen, pH, nitrogen, phosphorous, suspended solids, turbidity, conductivity, and temperature (see Appendix B for a description of these parameters). Water quality data are analyzed based on the water year, which is not the same as the calendar year. A water year is the 12-month period from October 1st through September 30th. The water year is a useful way to look at water data, because it starts at the beginning of the “wet season” and extends to the end of the “dry season.” The water year is designated by the year in which it ends. This report card for the 2010 water year includes water data from October 1, 2009 – September 30, 2010.

In addition to analyzing water samples, Pierce County monitors stream health by looking at the organisms that live in the water. The method we use involves collecting and counting the number and kinds of bugs (“benthic macro invertebrates”) living along the bottom of the stream. Samples are collected from each stream at least once every five years. The types of bugs present, and their relative numbers, can tell a lot about the general health of the stream. How are the measurements used? Water measurements are modeled using a Water Quality Index (WQI) method developed by the U.S. EPA and the Washington Department of Ecology.

The WQI is a single unit less number that expresses overall water quality at a certain location and time based on the monitored water quality parameters. In general, stations scoring 80 and above met expectations for water quality and are of “lowest concern,” scores 40 to 80 indicate “marginal concern,” and water quality at stations with scores below 40 did not meet expectations and are of “highest concern.”

Pg. 5 The WQI is a useful way to turn complex water quality data into an easily understood form. The WQI helps us prioritize which streams need action. More information on this method can be found in Appendix B.

The benthic macroinvertebrate samples are sent to a laboratory that analyzes the samples for ten “metrics,” including the number of species present and the ratio of pollution-tolerant and pollution-intolerant species. Like the WQI, the measurements are aggregated into an index. The index we use is the Benthic Index of Biotic Integrity (BIBI). The BIBI index ranges from 10 (poor) to 50 (excellent). More information on this method can be found in Appendix C.

What do the grades mean? Water Year 2010 Results The report card grades range from “A,” the The average grade for Pierce County streams in Water highest grade possible (excellent health) to “F,” Year 2010 was “C.” Water quality and aquatic habitat the lowest grade (very poor health). conditions can be considered “fair.” The data indicates a mix of good and poor levels of water quality and An initial grade is calculated by averaging the biological indicators. The average grade for 2009 was WQI and the BIBI grades. Some streams are also a “C.” Although County average stream health has listed on the Washington State Department of not improved, it has not worsened. Ecology’s List of Polluted Waters, or “303(d) list.” This list is based on Section 303(d) of the There are no “A’s” in this 2010 report card. The health of federal Clean Water Act, which requires states the sampled streams varied from good (B) to poor (D+). to identify and list water bodies that do not Of the 30 streams monitored, Clover, Nelyaly, and Swan meet state water quality standards, and to creeks received the lowest score and Canyon and Lynch create plans for cleaning them up. Streams on creeks received the highest score. the 303(d) list are reduced another 1/3 grade for each listed water quality problem such as Data were compared to 2009 results. Grades improved temperature, low dissolved oxygen, or fecal in twelve streams, declined for nine, and stayed the coliform bacteria. same for seven.

A table showing the grade ranges is included At the watershed level, the average grades changed only in Appendix A. An “A” grade indicates that slightly between 2009 and 2010. The KGI watershed all water quality and biological indicators improved from C- to C, the Puyallup and Nisqually meet expectations. Water quality and aquatic watersheds remained at C+ and C, respectively, and the habitat conditions tend to be excellent. An “F” Chambers-Clover Watershed remained at D+. grade indicates that water quality and habitat conditions tend to be poor. An “N/A” means Of the 30 streams monitored, six are listed on the 303(d) that not enough BIBI data was available to list of polluted waters maintained by the Washington generate a grade for that water year. Department of Ecology. No streams in Pierce County have been removed or added to the 303(d) list since the A list of 303(d) water bodies in Pierce County 2008 Water Quality report card was published. can be found in Appendix D.

Pg.6 Probable contaminants and sources

Approximately 800,000 people live in Pierce County. The most common water quality concerns in Pierce County streams are bacteria, high levels of nitrogen and phosphorus, high temperature and low oxygen concentrations.

Our daily actions impact the health of our local waterways. Stormwater PHOTO runoff picks up pollutants such as fertilizer, vehicle fluids and brake pad residue, pesticides, car wash soap, and bacteria from pet waste. Air Water Year 2010 Results pollution can also be captured by rainfall and carried into runoff. This Creek being runoff is often not treated before it reaches our streams, rivers, lakes, and Puget Sound. This can adversely impact water quality, which in tested or turn impacts fish and wildlife resources and human uses. Failing septic systems can contribute to increased nitrogen and bacteria in natural drainages. Runoff from exposed soil in farms and construction sites a visible can increase bacteria, turbidity, nitrogen and phosphorus. Increased nutrients can increase plant and algae production in streams, driving contamination down dissolved oxygen concentrations.

Sampling for Water Quality How can you help? The effort to protect and improve our natural waterways cannot be successful without residents becoming actively involved. A few things you can do are:

Know Your Local Creeks: Learn what creeks are near you. Volunteer to work on a BIBI data collection team. Contact Pierce Stream Team at (253) 845-2973 or e-mail [email protected] In Your Yard: Use fertilizer and pesticides sparingly, or just use compost. Visit www.tpchd.org/naturalyardcare. Manage Rainwater: Help rain soak into the ground by directing downspouts to a rain garden or vegetated area. Visit www.pierce.wsu.edu/lid With Your Car: Use a fish-friendly car wash and have oil leaks fixed. Visit www.piercecountywa.org/carwash Use Your Car Less: Check out other options at www.piercetrips.com With Your Dog: Pet waste is full of bacteria - Scoop up dog poop, bag it, tie securely and place it in the trash. Visit www.piercecountywa.org/petwaste Cleaning Your Home: From cleaning supplies to septic maintenance, be aware of how you care for your home. Visit www.tpchd.org and search under safety around the home. Maintaining Your Septic System: For information, contact the Tacoma Pierce County Health Department at (253) 798-3811 or www.tpchd.org/septic Disposing of Your Household Hazardous Waste: Do not pour used oil or chemicals into the drain. Visit www.piercecountywa.org/hhw Managing your Prescriptions and Personal Care Product:For more information, visit www.epa.gov/ppcp

Pg. 7 Watersheds In Pierce County

Pg. 8 Watersheds In Pierce County

LEGEND:

0 5.5 11 mi

Approximate Scale

Pg. 9 KGI Watershed Key Peninsula - Gig Harbor - Islands

Water Quality Monitoring Station Monitored Streams About the KGI Watershed About 80% of the 158 square-mile Key Peninsula- Gig Harbor- Islands Watershed is located in Pierce County. The Pierce County portion is composed of two large peninsulas, commonly referred to as the Gig Harbor Peninsula and the Key Peninsula. Much of the KGI watershed is rural, with urban centers in Purdy, Key Center, and Gig Harbor. Most residents live along the watershed’s 144 miles of salt and freshwater shoreline. Failing on-site septic systems and their impact on shellfish beds in Puget Sound are a major local concern. Pierce County acquires state and federal funding annually for an on-site septic repair grant/loan program.

Goodnough Creek and Dutcher Creek showed slight improvements in water quality scores in Water Year 2010. Both showed decreases in dissolved nutrients (nitrogen and phosphorus).

Minter Creek

Pg. 10 Creeks with Monitoring Stations

Artondale Creek (MS016) GRADE - C- Drains a 3.2 square mile area. The main stem of the creek originates in the ridge lands east of Rosedale, and flows easterly through the Gig Harbor Golf Club to Wollochet Bay. Coho and cutthroat use the creek. Crescent Creek (MS018) GRADE - C Drains a 6.5 square mile area. Crescent Creek flows south from its headwaters at Crescent Lake, follows Crescent Valley Road, and outlets into the bay at Gig Harbor. Coho, chum, steelhead, cutthroat, and Chinook use the creek. Dutcher Creek (MS065) GRADE - B- Drains a 3.3 square mile area. The creek begins near Key Center and flows south/southwest into Dutcher Cove on the west side of the Key Peninsula. The creek supports cutthroat, chum, and coho. Goodnough Creek (MS056) GRADE - C- The main stem is about one-mile long and drains an area of about 2.0 square miles. The headwaters of the creek are in the Canterwood Golf Course and Country Club. The creek flows westward under SR 16 before discharging to Henderson Bay just south of Purdy. The stream supports coho and chum salmon below SR 16. Cutthroat trout are also present.

Mark Dickson Creek (MS072) GRADE - C Drains a valley north of Arletta with an area of 2.2 square miles. It joins into Ray Nash Creek and flows into a small tidal inlet south of Raft Island. The main stem is about one mile long. The lower reaches of the main stem and the tributary from Sylvia Lake support coho and chum salmon, and possibly cutthroat trout. McCormick Creek (MS017) GRADE - C- Drains a 2.5 square mile area, much of which is in the City of Gig Harbor. The northern branch of the creek drains an area near the Canterwood Golf Course and Country Club. The southern branch drains a series of wetlands alongside Bujacich Drive. The creek passes under SR 16 and empties into Henderson Bay. McCormick Creek supports chum and coho salmon, steelhead and cutthroat trout. Chinook salmon strays have been noted. Minter Creek (MS089) GRADE - C Drains an 8.5 square mile area. It is 6.3 miles long with two major tributaries (Little Minter Creek and Huge Creek). It originates in Kitsap County north of Pine Road and flows south into Minter Bay. Minter Creek is on the 303(d) list due to high fecal coliform bacteria and low dissolved oxygen. Chinook, coho, chum, cutthroat, and steelhead use this creek. Nelyaly Creek (MS051) GRADE - C Drains a 1.5 square mile area northeast of Lay Inlet. The creek crosses under 92nd Street and empties to an arm of Lay Inlet. Volunteers have planted coho and chum for a number of years with reported high rate of hatching and returns. Purdy Creek (MS069) GRADE - C This 3.5 square mile long creek begins north of Burley Olalla road and flows south into Burley Lagoon. It is on the 303(d) list due to low dissolved oxygen. Chinook, steelhead, coho, chum, and steelhead use the creek. Ray Nash Creek (MS050) GRADE - C- Drains a 2.2 square mile area north of Arletta and joins Mark Dickson Creek before emptying into a small tidal inlet south of Raft Island. Coho, cutthroat, and chum use the creek. Rosedale Creek (MS052) GRADE - C+ Drains a valley north of Rosedale with an area of 0.6 square miles. It meanders south then west, crosses under Rosedale Street, and empties into a tidal inlet near Rosedale. The main stem of the creek is about 0.75 miles long. The creek supports coho and chum salmon and cutthroat trout in the lower reaches.

Pg. 11 Puyallup River Watershed

Water Quality Monitoring Station Monitored Streams About the Puyallup River Watershed The Puyallup River Watershed is the largest watershed in Pierce County, beginning at Mount Rainier and draining to Puget Sound via major rivers including the Carbon, White and Puyallup. Most of the upper watershed is national park, forest, and rural areas. The lower part of the watershed is urbanized, and includes the cities of Puyallup, Fife, Sumner, and Auburn (in King County), and Tacoma.

Water quality in the middle upper watershed is threatened by agriculture, forestry, and mining. The lower watershed is impacted by more urban stressors such as road and storm runoff, development, pollution, and clearing of vegetation.

Fennel Creek

Pg. 12 Creeks with Monitoring Stations Canyon Creek (MS011) GRADE - B Drains a 2.2 square mile area. The creek begins north of 128th Street East and flows north where it joins into Clear Creek and then the Puyallup River. Canyon Falls Creek (MS007) GRADE - C+ Drains a 1.71 square mile area. The creek cuts through a deep ravine on the east wall of the Puyallup Valley, flows through the valley and empties into the Puyallup River near McMillan. Chinook, pink, chum, coho, and steelhead use the creek. Clear Creek (MS012) GRADE - C- Drains a 5.2 square mile area. The creek originates near SR 512 in the Summit-Waller area, and drains north to the Puyallup River. It supports Chinook, steelhead, bull trout, coho, pink, chum, and cutthroat. Diru Creek (MS074) GRADE - C+ Drains a 1.3 square mile area. The creek begins near 128th Street East and flows into Clarks Creek north of Pioneer Way. Fennel Creek (MS008) GRADE - B- Drains a 6.58 square mile area. The creek is eight miles long, and begins north of SR 410 near Bonney Lake. It flows into the Puyallup River. Chinook, coho, pink, chum, and steelhead use the lower reach of the creek. Kapowsin Creek (MS032) GRADE - C+ About 3.6 miles long, it begins at the north end of Lake Kapowsin and flows into the Puyallup River. Chinook, pink, coho, steelhead and chum use the creek. Rody Creek (MS048) GRADE - C+ 1.6 miles long, and drains a 1.2 square mile area and is about 1.6 miles long. The creek begins south of SR 512 and flows north into Clarks Creek. Chum use the creek. Spiketon Creek (MS029) GRADE - C Drains a 3.3 square mile area. The creek begins near the Town of Buckley and flows into South Prairie Creek 1.5 miles upstream of the Town of South Prairie. Squally Creek (MS073) GRADE - B- Drains a 0.9 square mile area. It begins south of 72nd Street East and flows north into Clear Creek at Pioneer Way, which then joins the Puyallup River. Chum and coho use the lower stretch of the creek. Swan Creek (MS013) GRADE - D+ Drains a four square mile area. The creek begins south of SR 512 and flows north into Clear Creek, which then joins the Puyallup River. The creek is on the 303(d) list for high fecal coliform bacteria. Coho and chum use this creek. Voight Creek (MS033) GRADE - B- Drains a 23 square mile area. The creek begins on the northwestern slopes of Mt. Rainier and joins the Carbon River just upstream of the Town of Orting. Chinook, coho, pink, chum and steelhead use the creek.

Wilkeson Creek (MS030) GRADE - C Begins in the Mt. Baker-Snoqualmie National Forest and is about 12.3 miles long. It flows through the Town of Wilkeson and joins South Prairie Creek east of the Town of South Prairie. Salmon and steelhead use the lower half of the creek.

Pg. 13 Nisqually River Watershed

Water Quality Monitoring Station Monitored Streams

About the Nisqually River Watershed Like the Puyallup River system, the Nisqually watershed originates at Mount Rainier. The Nisqually River drains a 760 square mile area before reaching Puget Sound. The watershed includes a number of smaller communities such as Ashford, Elbe, Mineral, Eatonville, McKenna, Roy, and Yelm, and the southern portion of Joint Base Lewis-McChord. The watershed contains remnants of oak-prairie habitat unique to the region. The watershed also contains numerous freshwater streams. With abundant wildlife and natural landscapes, community groups are especially concerned with maintaining surface water health.

Ohop Creek Restoration Site

Pg. 14 Water quality has remained fairly steady since 2008. Water quality is of moderate concern. Woodlands, field and pasture land comprise a significant portion of the Nisqually Watershed. In rural areas, organic matter such as manure can be washed into streams. Also, much of the area depends on the on-site septic drain fields for sewage treatment. The introduction of too much organic matter to the streams increases biochemical oxygen demand, which means less dissolved oxygen is available for aquatic life. The introduction of untreated or insufficiently treated animal or human waste also increases the possibility of bacterial contamination of water, and excessive growth of algae. This in turn can drive down the amount of dissolved oxygen in the stream, which harms fish and other organisms living in the stream.

Creeks with Monitoring Stations

Horn Creek (MS024) GRADE - C- Drains an eleven square mile area. The creek begins near the intersection of SR 7 and SR 702 and flows southwest into the Nisqually River. Chinook, coho, pink, and steelhead use the creek. Lacamas Creek (MS078) GRADE - C+ Seven miles long and drains an eleven square mile area. It begins south of Joint Base Lewis-McChord and flows northwest through Roy and into Muck Creek. Coho and steelhead use the creek. Lynch Creek (MS027) GRADE - B Begins in the foothills northeast of Eatonville, and drains a 17 square mile area before joining Ohop Creek near Eatonville. Chinook, pink, coho, and steelhead use the creek. Ohop Creek (MS026) GRADE - C+ Originates in the foothills northeast of Eatonville, and flows southwest through Ohop Lake and eventually joins the Nisqually River. Chinook, pink, coho, and steelhead use the creek. Tanwax Creek (MS025) GRADE - C Drains an area of about 28 square miles and is over 13 miles long, It begins at Lake Kapowsin, flows through Lake Tanwax, and continuing southwest to the Nisqually River. Chinook, pink, coho, and steelhead use the creek.

Pg. 15 Chambers - Clover Watershed

Water Quality Monitoring Station Monitored Streams About the Chambers - Clover Watershed The Chambers - Clover Creek Watershed covers a 149-square mile area. It extends from the town of Ruston on Commencement Bay, south to DuPont, and east to Frederickson. The watershed contains a number of lakes including American, Spanaway, Steilacoom, Gravelly, and Tule.

The major streams in the watershed are Chambers, Clover, Spanaway, Morey, Murray, Flett, Leach, Puget, and Peach. Water quality and BIBI samples are collected in Spanaway Creek and Clover Creek. Both Spanaway Creek and Clover Creek have show consistent yet poor water quality characteristics in since monitoring began in 2008.

Upper Clover Creek

Pg. 16 The Chambers - Clover Creek Watershed receives runoff from the most urbanized portion of the county. It receives drainage from seven municipalities (Tacoma, Ruston, Fircrest, University Place, Lakewood, Steilacoom, and DuPont), Camp Murray, and the north portion of Joint Base Lewis-McCord. Water quality in the Chambers - Clover Creek Watershed has deteriorated substantially as the area has become urbanized over the past century. While the bodies of water in this watershed are still important habitat for salmon, urbanization has resulted in stream degradation from impacts such as heavy recreational use, increase in impervious surfaces, clearing of streamside vegetation, pet waste, vehicle emissions and leaks, pesticide and fertilizer use, leaking from underground storage tanks, and untreated urban and stormwater runoff.

Domestic sewage in the eastern half of the Chambers - Clover Creek area is typically treated in septic tanks and drainfields. The sandy and gravelly soils characteristic of this area readily accepts septic tank effluent, but may not sufficiently treat it before it moves into groundwater. This also makes it difficult to control leachate from the existing solid waste disposal landfills and underground storage tanks within the watershed.

Pet waste and car washing can also be significant water pollutants in urban watersheds. Pet waste should be bagged and disposed of in the garbage, to control the spread of bacteria and nutrients to streams in the Chambers-Clover Creek area. Cars should be washed in areas that drain to a sewage treatment facility, or over grassy areas.

Creeks with Monitoring Stations

Clover Creek-North Fork (MS080) GRADE - D+ About the Chambers - Clover Watershed Drains a 74 square mile area. The creek begins near the Frederickson industrial area, and flows west for nine miles across the Joint Fort Lewis-McChord base before flowing into Steilacoom Lake. Steelhead and Coho use the creek.

Spanaway Creek (MS006) GRADE - C- The creek begins at the outlet of Spanaway Lake, and is therefore impacted by water quality issues in the lake. These include higher water temperature and low dissolved oxygen. Residential development borders much of the stream, with minimal streamside vegetation. Coho use the stream.

Pg. 17 Monitored Lakes in Pierce County

How is lake health monitored? Many agencies and citizen groups are monitoring the health of lakes in Pierce County. The data in this year’s report card was provided by the City of Lakewood Volunteer Lake Monitoring Program coordinated by Pierce Stream Team; University of Washington – Tacoma, and the Tacoma-Pierce County Health Department.

Many lake characteristics can be used to assess the lake’s overall health. In this report, the grade assigned to each lake is based on three water quality parameters (total phosphorus, chlorophyll a, and Secchi depth), and on the lake’s ability to support swimming and recreation uses (toxic algae and swimming beach advisories).

The six lakes included in this year’s report card are within the Chambers-Clover Creek Watershed. The grades assigned this year will serve as a “baseline” for comparison with future grades.

How are grades assigned? Many lake characteristics can be used to assess a lake’s overall health. In this report, the grade assigned to each lake is based on four water quality parameters (total phosphorus, chlorophyll α, Secchi depth, and E. coli bacteria), and on the lake’s ability to support swimming and recreation uses (toxic algae and swimming beach advisories).

Pg. 18 Each of these factors has its own grading scale based on scientific research, state standards, and local knowledge of lakes in Pierce County. Like a school report card where a grade is assigned for each subject, a grade is assigned for each of these factors. For each lake, the grades for the factors are averaged to produce an overall grade. If the lake is on the state 303d list of polluted waters, the final grade is lowered more. Grades range from A for good water quality, to F for very poor water quality and possible hazards to human health. More detailed information on lake grades and the grading system can be found in Appendix F.

Lakes being monitored Detailed lake grades can be found in Appendix G

American Lake GRADE - B American Lake is the largest natural lake in Pierce County, covering an area of 1100 acres. The lake has a maximum depth of 90 feet, a mean depth of 53 feet, and a drainage area of about 25 sq. miles. The lake is supplied by groundwater and Murray Creek. The lake has a controlled outflow to Sequalitchew Creek. The lake receives heavy recreational use and two Lakewood City parks are located along its shores.

Gravelly Lake GRADE - B+ Gravelly Lake, located just northeast of American Lake, covers an area of 160 acres. The lake has a maximum depth of 55 feet and an average depth of 38 feet, and drains an area of less than one square mile. The lake is almost entirely groundwater fed although there is no public access, the lake supports boating, fishing, and swimming.

Lake Louise GRADE - B+ Lake Louise is located southeast of the Town of Steilacoom and covers an area of 39 acres. It has a maximum depth of 35 feet and an average depth of 22 feet. The lake has no surface inlets or outlets and is primarily groundwater fed with a drainage area of about 0.34 sq. miles. The lake does not have a public beach, but it does have a public boat launch and is heavily used for boating, fishing, and swimming.

Spanaway Lake GRADE - C+ Spanaway Lake, located in the Spanaway area is 280 acres in size. The lake is fed by Coffee Creek and drains through Spanaway Creek. The lake drains an area of 17 sq. miles, has a maximum depth of 28 feet, and an average depth of 16 feet. Spanaway Lake has a large county park located at the northeast end and supports heavy recreational use.

Steilacoom Lake GRADE - D+ Steilacoom Lake was formed in 1852 when early settlers built a dam on Chambers Creek. The lake covers 320 acres and drains an area of a little more than 89 sq. miles with a maximum depth of 20 feet and an average depth of 11 feet. Ponce de Leon and Clover Creeks feed the lake, while outflow is through Chambers Creek. Steilacoom Lake has a public boat launch and is heavily used for boating, fishing, and swimming.

Wapato Lake GRADE - C Wapato Lake is a 28-acre lake located east of I-5 near the 74th Street interchange in the City of Tacoma. The lake has a maximum depth of 13 feet and an average depth of 5 feet. The lake receives most of its water from two storm drain inlets on the north end of the lake with outflow directed to Wards Lake. The lake, surrounded by Wapato Park, has a drainage area of just under two square miles. Wapato Lake historically received heavy recreational use, but has been closed to swimming and boating in recent years due to water quality problems including high bacteria counts and toxic algae blooms.

Pg.19 Appendix A Determining Stream Grades

We use data collected for BIBI and WQI to determine an average grade for each stream. Grades are calculated using the following steps: 1. Convert BIB to a 0-100 scale. (BIBI) x 2 = %BIBI 2. Average the BIBI and WQI. 3. If the stream is on the 303(d) list, reduce the first value by 1/3 grade (6.5 points) for each water quality impairment identified for that stream. If the stream is not on the 303(d) list, skip this step and proceed to Step 4. 4. Determine the letter grade based on the grading below. Grading Index

Score is greater And score is Grade Status Description than or equal to: less than: 0 28 F Very poor Very few or no water quality and biological indicators meet the expectation. Water quality and aquatic habitat conditions tend to be poor. 28 35 D- 35 41 D Poor Some or few water quality indicators meet the expectation. Water quality and aquatic habitat conditions tend to be very poor. 41 48 D+ 48 55 C- 55 61 C Fair Mix of good and poor levels of water quality and biological indicators. Water quality and aquatic habitat conditions tend to be fair. 61 68 C+ 68 74 B- 74 80 B Good Most water quality and biological indicators meet expectations. Water quality and aquatic habitat conditions tend to be good. 80 86 B+ 86 93 A- 93 100 A Excellent All water quality and biological indicators meet expectations. Water quality and aquatic habitat conditions tend to be excellent.

Pg. 20 Appendix B Methodology and the Water Quality Index

Methodology Dissolved oxygen The grades are based on a normalized and averaged When oxygen is in water, it is in a dissolved form. In score using WQI and BIBI, with a penalty for each this form, it is available to fish, invertebrates, plants, parameter listed on the State’s 303(d) list. and other organisms living in the water. Excess nutrients in the water may increase biological activity, State water quality standards strive to protect the using up available dissolved oxygen. Increase in water beneficial uses of our waters, such as recreation and temperature reduces the amount of dissolved oxygen aquatic habitat. Water quality data varies in place and the water can hold. Low levels of oxygen in the water are time, but a 303(d) listing indicates significant impairment therefore a sign of possible degradation. over time. The 303(d) listing is based on multiple parameters, each a possible violation of adopted state pH water quality standards. Scores are reduced by 1/3 PH is a measure of the acid content of the water. Most grade (6.5%) for each 303(d) parameter. For example, aquatic organisms are very sensitive to pH. In Pierce the grade of a stream having three parameters (such as County, a healthy stream pH is typically between 6.5 and fecal coliform, dissolved oxygen, and temperature) on 8.5. External factors can adversely affect the pH. Lime the 303(d) list is reduced by 19.5%. soil additives and fertilizers can increase the pH, while “acid rain” created by fossil fuel combustion can reduce Grading based on the WQI, BIBI and 303(d) list paints a the pH. more representative and useful description of stream health than each factor viewed individually. Temperature Salmon and trout need high levels of dissolved oxygen Water Quality Index and water temperatures not above 61°F to survive and The Water Quality Index (WQI) is a unit less number reproduce. Warm temperature reduces the amount ranging from 1 to 100, with a higher number indicating of dissolved oxygen in the water and threatens our better water quality. Eight parameters are measured native species. External factors that can increase water monthly to determine the WQI. temperature include removing streamside vegetation, ground water withdrawal, eroding stream banks, and Laboratory and field results are recorded and transferred runoff from paved areas. to a curve chart where a numerical value is obtained. The curves are based in part on state standards Total Nitrogen and Phosphorus developed to maintain beneficial uses of waters, such as High levels of these nutrients cause excessive algae and recreation, drinking water, and aquatic habitat. For each plant growth. When these plants die, they decompose. test, the numerical value is multiplied by a “weighting Both of these processes consume large amounts of factor.” Some parameters are given more “weight” than available oxygen. Common sources of nitrogen and others because they are more significant in determining phosphorous are fertilizers, and human and animal water quality than the others. The nine resulting values waste. are then added to arrive at an overall WQI.

Fecal Coliform Bacteria Fecal coliform bacteria are found in the intestines of warm-blooded animals. Its presence indicates fecal matter in the water and the potential for other disease- causing organisms. It is a health risk for humans to be exposed to water high in fecal coliform concentration.

Pg. 21 Appendix B (Continued) Methodology and the Water Quality Index

Total Suspended Solids Total suspended solids refers to that portion of the sediment load suspended in the water column, instead of sinking to the stream bottom. High concentrations of suspended solids can harm aquatic life by blocking sunlight and reducing plant photosynthesis, clogging fish fills, and increasing surface water temperature. There are natural sources of suspended solids such as glacial melt water, as well as human sources such as agriculture, logging, surface mining, and construction.

Turbidity Turbidity is a measure of water clarity. Things such as algae, organic acids, and suspended solids can increase turbidity. Particle suspended in the water absorb heat from sunlight, increasing water temperature and reducing dissolved oxygen. Heavy metals and other toxic substances can also attach to suspended materials. High turbidity can block sunlight, decreasing plant and algae photosynthesis, affecting the food chain for fish.

Conductivity Conductivity refers to the ability of a substance to conduct an electric current. Conductivity measurements indicate the number of dissolved ions (positive or negative charged particles) in the water. Conductivity data can help characterize overall stream chemistry, and its effects on plants and animals. Changes in conductivity can rapidly indicate that pollutants from sources like agriculture or wastewater are entering and dissolving into a stream. Conductivity is also useful in determining how large a water sample is needed for laboratory analysis, and what treatment chemicals are needed to make water suitable for drinking or discharge.

Pg. 22 Appendix C Benthic Index of Biotic Integrity (BIBI)

A healthy stream system contains a wide variety of species, supports greater numbers of these species, and allows for their successful reproduction and resistance to disease. The Benthic Index of Biotic Integrity (BIBI) is a method based on these concepts. BIBI is a unique water quality monitoring tool because it is based on what is living in the stream instead of on stream chemical or physical properties.

The BIBI is based on surveys of macro-invertebrates, which are creatures without backbones that live on the stream bottom. Some examples include insects, crustaceans, worms, snails, and clams. Macro-invertebrates play an important role in the stream food chain as an intermediate link between microscopic organisms and fish. Macro-invertebrates are useful indicators of stream quality because they spend their life cycle in a small area, they have a short life span, and they are sensitive to changes in water pollution.

Pierce County monitors stream health by collecting samples of macro invertebrates from the bottoms of selected streams at least once every five years. A number of biological attributes, called metrics, are analyzed and consolidated into a score for the stream. By using this scoring system, we can compare different streams with each other.

Different macro-invertebrate species have various levels of tolerance for pollution. Some species, such as mayfly, stone fly, and caddis fly are very intolerant to pollution. In an unhealthy stream, numbers of these species may decline, while numbers of more tolerant species like leech and black fly larvae may increase. Because macro-invertebrates can’t escape like fish can, macro monitoring allows for long-term, ambient detection of deteriorating stream conditions.

Pierce County contributes BIBI data to a regional monitoring program that is tracking biotic integrity throughout Puget Sound. For information visit http://pugetsoundstreambenthos.org

Stonefly Riffle Beetle

Riffle Beetle Stonefly Dobsonfly

Pg. 23 Appendix D Section 303(d) List

The list of lakes, streams, and rivers in Pierce County that have been designated by the Washington Department of Ecology as impaired by pollutants. Impaired means that the water is not meeting state water quality standards. Streams highlighted in red are those included in this report card.

Waterway/Waterbody Parameter failing standards Waterway/Waterbody Parameter failing standards American Lake 2, 3,7, 8-TCDD, Dieldrin, PCB, Nisqually Reach/Drayton Fecal Coliform Total Phosphorus Passage Balch and Cormorant PCB North Creek Lead Passages Ohop Creek DO Berry Creek Temperature Ohop Lake Total Phosphorus Boise Creek Fecal coliform Picnic Creek Fecal Coliform, pH Case Inlet and Dana Pas- PCB, DO, Fecal Coliform Private Creek Fecal Coliform, pH sage Purdy Creek DO Chambers Creek Bioassessment, Fecal Coliform Puyallup River Fecal Coliform, Mercury Clarks Creek pH, Fecal Coliform Ravine Creek Fecal Coliform Clearwater River Temperature Salmon Creek Fecal Coliform Clover Creek Temperature, DO, Fecal Coliform School Creek Fecal Coliform Colvos Passage PCB Spanaway Lake Fecal Coliform Commencement Bay PCB, DDT, HPAH, Chlorinated (Inner) Pesticides, Dieldrin Steilacoom Lake Sediment Bioassay, Total Phos- phorus Commencement Bay BIS(2-Ethylhexyl) Phthalate, PCB, (Outer) DO Summit Lake pH Dalco Passage/Poverty PCB, DO Swan Creek Fecal Coliform Bay Wapato Creek Bioassessment, DO, Fecal Coli- Deer Creek Fecal Coliform form Fife Ditch Fecal Coliform, Ammonia-N, DO Wapato Lake Fecal Coliform Fox Creek Temperature White River Temperature, pH, Fecal Coli- form Hale Passage (South) PCB Woodland Creek Fecal Coliform Harts Lake Total Phosphorus Unnamed Creek (trib to Fecal Coliform Henderson Bay Fecal Coliform Clover Creek at 99th St) Huckleberry Creek Temperature Unnamed Creek (trib to Fecal Coliform Huge Creek Dissolved Oxygen Clover Creek at Bingham Hylebos Creek Bioassessment, Fecal Coliform Ave) Kings Creek Temperature Unnamed Creek (trib to Fecal Coliform Clover Creek at Brookdale Lagoon Creek pH Rd) Leach Creek Mercury Unnamed Creek (trib to Fecal Coliform Little Minter Creek Fecal Coliform Filucy Bay) Lyle Creek Temperature Unnamed Creek (trib to Fecal Coliform Mashel River Temperature Puyallup River) Mayo Creek Temperature, Fecal Coliform Unnamed Drain (trib to DO Meeker Ditch Fecal Coliform, pH, DO Ohop Creek) Milky Creek Temperature Minter Creek Fecal Coliform, DO

Pg. 24 Appendix E Water Year 2010 Stream Health Data Summary and Grade Assignment

Station Creek Name BIBI- WQI 303(d) Points Score= Final Water 2008 Number Ave. of List? Lost (6.5 (%BIBI + Water Year Base- Available points lost WQI)/2 Year 2009 line Scores for each – 303(d) 2010 Grade Grade from last 303(d) points Grade 6 years Listing) lost

MS016 Artondale 25 51 No 0 50.5 C- C C+ MS011 Canyon 33 92 No 0 79.0 B B B- MS007 Canyon Falls 18 87 No 0 61.5 C+ C C+ MS012 Clear 13 75 No 0 50.5 C- D+ D+ MS080 Clover 22 78 Yes -19.5 41.5 D+ D D MS018 Crescent 29 60 No 0 59.0 C C+ C MS074 Diru 24 87 No 0 67.5 C+ C+ C MS065 Dutcher 27 82 No 0 68.0 B- C C MS008 Fennel 30 85 No 0 72.5 B- B- C+ MS056 Goodnough 23 59 No 0 52.5 C- D+ C+ MS024 Horn 28 41 No 0 48.5 C- C C MS032 Kapowsin 26 73 No 0 62.5 C+ C+ C MS078 Lacamas 32 67 No 0 65.5 C+ C- C- MS027 Lynch 34 91 No 0 79.5 B C+ B- MS072 Mark Dickson 30 61 No 0 60.5 C C C+ MS017 McCormick 22 63 No 0 53.5 C- C- C MS089 Minter 26 88 Yes -13 57.0 C C- C+ MS051 Nelyaly 20 72 No 0 56.0 C C- C- MS026 Ohop 36 66 Yes -6.5 62.5 C+ C C MS069 Purdy 29 65 Yes -6.5 55.0 C C C MS050 Ray Nash 25 59 No 0 54.5 C- C- C MS048 Rody 22 90 No 0 67.0 C+ C C- MS052 Rosedale 21 81 No 0 61.5 C+ C C MS006 Spanaway 17 71 No 0 52.8 C- N/A C- MS029 Spiketon 26 67 No 0 59.5 C N/A C+ MS073 Squally 27 83 No 0 68.5 B- C B- MS013 Swan 24 60 Yes -6.5 47.5 D+ C- C MS025 Tanwax 27 61 No 0 57.5 C C+ C MS033 Voight 31 80 No 0 71.0 B- C C+ MS030 Wilkeson 27 60 No 0 57.0 C C+ B-

Pg. 25 Appendix F More Information on Lake Grades

Monitored lakes grades are calculated as follows: 1. A lake receives a single grade for each factor, except for the Swimming Beach Category. Swimming Beach advisories are generally issued by the Tacoma Pierce County Health Department when two consecutive lake samples have high E. coli bacteria counts. The Swimming Beach advisories and E. coli GMVs have been averaged together into one grade for Swimming Beaches. If a lake doesn’t have a monitored swimming beach in a given year, this would neither increase nor decrease the score for that lake. 2. Each grade is assigned a numerical value: A (12), A- (11), B+ (10), B (9), B- (8), C+ (7), C (6), C- (5), D+ (4), D (3), D- (2), and F (1). 3. To produce an overall average grade, the numerical values are added together, and divided by the total number of grades (arithmetic mean). 4. The overall average grade is marked down by 1/3 of a grade for each parameter that is on Ecology’s most recent 303(d) list for that particular lake. Lakes in this report card that are on the 303(d) list and the water quality parameter causing the listing include: American Lake (Total Phosphorus), Lake Steilacoom (Total Phosphorus), Spanaway Lake (Fecal Coliform), and Wapato Lake (Fecal Coliform). The report does not provide an exact comparison since the same types of data are not being collected for all of the lakes. For example, a lake without a swimming beach will not receive a grade for that factor. Some lakes might warrant listing or removal from the 303(d) list, but have not been due to insufficient monitoring. However, this report card provides a way to compare the quality of our lakes relative to one another and to other lakes in the Puget Sound basin.

Pg. 26 Appendix F (Continued) More Information on Lake Grades

How are the grades assigned?: Factor A (Grade) B C D F Secchi Depth (m): Deep Lakes >5 5.0 - 3.8 3.7 - 2.4 2.3 - 1.0 <1.0 Shallow Lakes >3 3.0 - 2.3 2.2 - 1.6 1.5 - 1.0 <1.0 Total Phosphorous (µg/L) <12 12 - 20 21 - 30 31 - 45 >45 Chlorophyll a (µg/L) <4 4 - 10 >10 - 18 >18 - 30 >30 Toxic Algae Advisory Caution Warning Closed Average: Swimming Beach Advisory & Advisory Issued E. coli (GMV)* <10 >10-20 >25-50 >50-126 >126 *(GMV) = Geometric Mean Value of coliform forming units (cfu), expressed as cfu/100 ml

More information about the grading system: Total Phosphorus (TP), Chlorophyll a, and Secchi Depth values are the arithmetic mean concentration of all samples collected or measurements taken at or near the surface over the deepest part of the lake from May through September (June through August on Spanaway Lake and June through September on Wapato Lake). The Secchi Depth grade varies depending on if it is a deep lake (greater or equal to five meters at its deepest spot) or a shallow lake (less than 5 meters in depth).

Swimming Beach advisories are generally issued when two consecutive samples have high E. coli counts. The Swimming Beach advisories and E. coli GMVs will be averaged together such that there is one grade for Swimming Beaches. For example, if a lake has an E. coli GMV of 32 and no advisories against swimming, the grade will be a C. If a lake has an E. coli GMV of 32 and has a “no swimming” advisory the grade will be a C- ([C + D]/2). American Lake and Spanaway Lake have two swimming beaches, so the arithmetic mean of the two beaches E. coli GMVs is used. If a lake doesn’t have a monitored swimming beach in a given year, this would neither increase nor decrease the score for that lake.

The intervals between grades for each parameter are not uniform. The intervals were selected based upon: • Criteria used in other regions of the United States and Canada (http://www.minnehahacreek.org/wq_ report_cards.php http://www.metrocouncil.org/environment/RiversLakes/Lakes/index.htm • Action levels and criteria in existing state guidelines and regulations. For example, Washington Administrative Code 173-201A-230 specifies that if Total Phosphorus is greater than 20 µg/L, a lake specific study may be initiated; • Literature values for trophic status index: Carlson, R.E. 1977. A Trophic State Index for Lakes. Limnol. Oceanogr. 22: 361-369; Welch, E. B. and T. Lindell. 1992. Ecological Effects of Wastewater – Applied Limnology and Pollutant Effects; and • Personal knowledge and professional judgment about lakes in this area.

Pg. 27 Appendix G Lake Data Summary & Grade Assignment

American Lake 2010 2009 2008 Factor Value Grade Value Grade Value Grade Secchi Depth (m): Deep Lakes 5.1 A 7.2 A 5.7 A Total Phosphorus (µg/L) 20 B 32 D 12 B Chlorophyll a (µg/L) 6 B 4 B 5 B Toxic Algae Advisory Caution C Caution C Caution C Average: Swimming Beach No Swimming A No Swimming A No Swimming A Advisory & Beach Advisory Beach Advisory Beach Advisory E. coli (GMV) 9.4 8.0 6.3 Average Grade 5.1 B+ B- B+ 303(d) Listing? Yes (Total Yes Yes Phosphorus) Final Grade B C+ B

Gravelly Lake 2010 2009 2008 Factor Value Grade Value Grade Value Grade Secchi Depth (m): Deep Lakes 4.8 B 6.8 A 8.3 A Total Phosphorus (µg/L) 8 A 14 B 4 A Chlorophyll a (µg/L) 5 B 2 A 4 B Toxic Algae Advisory No Advisory No Advisory No Advisory Average Grade B+ A- A- 303(d) Listing? No No No

Final Grade B+ A- A-

Lake Louise 2010 2009 2008 Factor Value Grade Value Grade Value Grade Secchi Depth (m): Deep Lakes 5.8 A 6 A 5.8 A Total Phosphorus (µg/L) 8 A 20 B 8 A Chlorophyll a (µg/L) 5 B 3 A 3.4 A Toxic Algae Advisory Caution C No Advisory No Advisory Average Grade B+ A- A 303(d) Listing? No No No

Final Grade B+ A- A

Pg. 28 Appendix G (Continued) Lake Data Summary & Grade Assignment

Spanaway Lake 2010 Factor Value Grade Secchi Depth (m): Deep Lakes 4.2 B Total Phosphorus (µg/L) 13 B Chlorophyll a (µg/L) 7 B Toxic Algae Advisory Warning D Average: Swimming Beach Advisory & No Swimming Beach Advisory A E. coli (GMV) 8.5 Average Grade B- 303(d) Listing? Yes (Fecal Coliform)

Final Grade C+

Steilacoom Lake 2010 2009 2008 Factor Value Grade Value Grade Value Grade Secchi Depth (m): Deep Lakes 3.3 C 3.5 C 3.6 C Total Phosphorus (µg/L) 38 D 18 B 28 C Chlorophyll a (µg/L) 15 C 6 B 12.4 C Toxic Algae Advisory Caution C Caution C Caution C Average Grade C- B- C 303(d) Listing? Yes (Total Phosphorus) Yes Yes

Final Grade D+ C+ C-

Wapato Lake 2010 Factor Value Grade Secchi Depth (m): Shallow Lakes 3 B Total Phosphorus (µg/L) 21 C Chlorophyll a (µg/L) 9 B Toxic Algae Advisory No Advisory Average: Swimming Beach Advisory & No Swimming Beach Advisory C E. coli (GMV) 42.0 Average Grade C+ 303(d) Listing? Yes (Fecal Coliform)

Final Grade C

Pg. 29 Appendix H Lake Report Card Factors

Secchi Depth Toxic Algae Secchi depth is a measure of water clarity. It is Toxic algae, also known as cyanobacteria or blue-green measured by lowering a Secchi disk (an 8-inch disk algae, may produce toxins. These toxins can kill pets, with alternating black and white quadrants) into a lake waterfowl, and other animals. They can also cause until it can no longer be seen. The depth at which serious illness or even death in people. Toxic algae the disk is no longer visible is called the Secchi depth. are naturally occurring but likely have increased due Higher Secchi depth readings indicate clearer water. to impacts from human activities. Toxic algae can Water clarity is affected by algae, sediment, and other reproduce rapidly and within a few days a “clear” lake, suspended materials in the water. Because water pond or ditch can become discolored with algae growth. clarity is most often affected by algae, Secchi depth is This is called a bloom. Toxic algae blooms often float to used as an indicator of algal abundance. the surface and can form a surface scum, which usually accumulates on the downwind shoreline. Total Phosphorus Phosphorus is one of two key nutrients found in lakes. Wind and weather conditions can greatly change the It is essential for growth of plants and algae, but the amount and location of algae. The Tacoma-Pierce presence of too much phosphorus can lead to nuisance County Health Department monitors toxic algae and growth of aquatic plants and algae. Total phosphorus issues advisories when conditions pose a health concern. is a measure of all forms of phosphorus present in the There are three advisory levels: Caution (lower level of lake. Phosphorus can come from a variety of external concern), Warning, and Closed (highest level of concern). sources including human and animal wastes, soil erosion, detergents, septic systems, runoff from lawns Algal Blooms in Spanaway & Steilacoom Lakes or agricultural lands and release of phosphorus from lake sediments (internal loading).

Chlorophyll a Chlorophyll is the green pigment found in all plants and algae and is necessary for photosynthesis. Chlorophyll a is the most abundant form of chlorophyll found in algae. Measurement of chlorophyll a concentrations in lakes is relatively easy and provides an indication of the amount of algae present.

Secchi depth, total phosphorus, and chlorophyll a are interrelated. For example, high concentrations of phosphorus in lakes can cause an increase in algae blooms (which increase the amount of chlorophyll a) which in turn will lead to a decrease in Secchi depth.

Pg. 30 Appendix H (Continued) Lake Report Card Factors

Swimming Beaches All rivers, streams, lakes, and ponds can naturally contain bacteria, viruses, parasites, and algae. Most of these small organisms are beneficial and don’t harm people, but some can cause illness. As funding allows, the Tacoma-Pierce County Health Department collects water samples for E. coli bacteria counts every other week during the summer from seven swimming beaches. If the water samples have high bacteria counts, an advisory is issued, recommending against swimming at the beach.

E. coli Bacteria Escherichia coliform (E. coli) bacteria are commonly found in the intestines of warm-blooded animals. Most E. coli are not in themselves harmful. High E. coli counts indicate high amounts of fecal material, which may in turn increase the risk of harmful bacteria. High counts of E. coli in swimming areas have been associated with increased incidence of illness in swimmers. The number of E. coli, as well as other bacteria, varies greatly in the Algal Blooms in Spanaway & Steilacoom Lakes environment.

To help reduce the influence of one or two very high counts or very low counts in calculating the average number of E. coli present over time, the geometric mean value (GMV) is used rather than the arithmetic mean. The GMV is calculated by multiplying all the results together and taking the nth root of the product, where n is the number of results entered into the calculation. This is different than the arithmetic mean, which is calculated by adding all the results together and then dividing the sum by the number of results.

303(d) list Water bodies that fail to meet water quality standards and are unlikely to meet those standards within the next two years are placed on the 303(d) list, named after the section of the Clean Water Act that requires all states to list polluted water bodies. The listing of a water body initiates a process leading to the development of a water clean-up plan also know as a Total Maximum Daily Load plan.

Pg. 31 2702 South 42nd Street, Suite 201 Tacoma, Washington 98409-7322 (253) 798-2725 www.piercecountywa.org/swm Pierce County

Grade: C 2010 Watershed Health Report Card Why it matters Pierce County routinely monitors streams and lakes for water quality. This report card reflects the current condition of our water bodies. Identifying current conditions is a critical step for preserving and improving stream and lake health. By combining information about physical, biological, and chemical characteristics, we get a baseline for continued study. You can find more about our methodology online at www.piercecountywa.org/monitoring.

Grading Scale All indicators and/or public health parameters meet A expectation. Water quality conditions excellent. Most indicators meet expectation. Water quality B conditions good. Mix of good and poor levels of indicators. Water quality C conditions fair. Some or few indicators meet expectation. Water quality D conditions poor. Very few or no indicators meet expectation. Water F quality conditions very poor. How do Streams Data collected through and Lakes in Pierce Stream Rating Grade Stream Rating Grade Diru Creek 67.5 C+ Purdy Creek 55.0 C water year 2010 ranks County Rate? Pierce County’s overall Dutcher Creek 68.0 B- Ray Nash Creek 54.5 C- Data collected through water year lake health at B- Fennel Creek 72.5 B- Rody Creek 67.0 C+ 2010 ranks Pierce County’s overall (Good Condition). Goodnough Creek 52.5 C- stream health at C (Fair Condition). Rosedale Creek 61.5 C+ Horn Creek 48.5 C- Spanaway Creek 52.8 C- The rating was 60.0 out of a possible 100.0. Lake Grade Kapowsin Creek 62.5 C+ Spiketon Creek 59.5 C American Lake B Stream Rating Grade Lacamas Creek 65.5 C+ Squally Creek 68.5 B- Gravelly Lake B+ Artondale Creek 50.5 C- Lynch Creek 79.5 B Swan Creek 47.5 D+ Lake Louise B+ Canyon Creek 79.0 B Mark Dickson Creek 60.5 C Tanwax Creek 57.5 C Spanaway Lake C+ Canyon Falls Creek 61.5 C+ McCormick Creek 53.5 C- Voight Creek 71.0 B- Steilacoom Lake D+ Clear Creek 50.5 C- Minter Creek 57.0 C Wilkeson Creek 57.0 C Wapato Lake C Clover Creek 41.5 D+ Nelyaly Creek 56.0 C Pierce County 60.0 C Pierce County B- Crescent Creek 59.0 C Ohop Creek 62.5 C+ Overall Overall