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Stormwater Strategies
Community Responses to Runoff Pollution

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Chapter 10


Addressing Stormwater in New Development and Redevelopment
Portland, OR | Portland Metropolitan Area, OR | Additional Examples

Promoting Public Education and Participation
Puget Sound, WA | Portland and Multnomah County, OR | Kitsap County, WA | Washington State Department of Transportation | Additional Examples

Controlling Construction Site Runoff
Eugene, OR | Washington State Department of Transportation | Additional Examples

Detecting and Eliminating Improper or Illegal Connections and Discharges
Mason County, WA | Portland, OR | Additional Examples

Implementing Pollution Prevention for Municipal Operations
Eugene, OR | Olympia, WA | Additional Examples

Addressing Stormwater in New Development and Redevelopment

Environmental Development at the Oregon Museum of Science and Industry

Portland, OR1
Population: 437,329
Area: 3,743 square miles

Highlight: Adjustments to building requirements enable stormwater-conscious design that is attractive, educational, easy to maintain, and less expensive than conventional design.

The Oregon Museum of Science and Industry was planning redevelopment of a 20-acre industrial site adjacent to the Willamette River in Portland, Oregon, to serve as the museum's new home. The redevelopment plans provided that impervious surface, including buildings and a 6-acre parking lot, would cover 50 percent of the site, with the rest remaining as vegetated land. In 1990, Portland's Bureau of Environmental Services reviewed the initial plans for the redevelopment and asked the museum to voluntarily make moderate changes for better stormwater pollution control.

Being environmentally sensitive appealed to the institution. But fearing cost overruns that it could not afford, the not-for-profit institution agreed to revise its plans only on the condition that the changes would neither increase the redevelopment costs nor interfere with the existing schedule for completion.

The stormwater redesign met both of the museum's requirements. The bureau did not ask the museum to alter the planned size or location of either the buildings or the parking lot; it merely suggested that the museum change the site grading and the design of the already-planned landscape medians. In the original design, rain ran away from the elevated landscape medians and across the parking lot into conventional storm sewer inlets, which then drained into storm sewers leading into the Willamette River. The bureau proposed to direct the stormwater into the medians, which would be redesigned as grass swales that would filter pollutants out of the stormwater before the water drained into the river. The museum took the redesign further by enlarging and redesigning the medians to retain water for a longer period of time. By planting the medians with native wetland vegetation, the museum created "mini linear wetlands."

Redevelopment costs fell as a result of the redesign. Museum staff testified before the city council in 1993 that the reduction in the number of manholes and catchbasinss, and the reduced amount of piping and trenching needed, resulted in a net savings of approximately $78,000 in construction costs, even after the additional design fees were taken into account. Although existing municipal policies and codes did not allow developers to use water-quality-sensitive site design, the city took the initiative and created a team of representatives from relevant public agencies to work with the museum and insure that the project advanced through approval processes in a timely fashion.

The redesign provided a number of benefits. A recent Portland water-quality audit estimates that the redesigned system removes 50 percent of the average annual TSS loading from the site, and minor design changes currently under consideration could increase this figure to 90 percent. Computer modeling indicates that the swales will infiltrate 0.83 inches of rainfall in a 24-hour period, which accounts for approximately three-quarters of Portland's average annual rainfall. Thus far, infiltration has exceeded expectations, with the only discharge to the city's storm sewer system occurring during extreme rainfalls. The swales' capacity for infiltration keeps the amount of standing water low, so that the swales do not provide breeding ground for mosquitoes. The museum considers the wetland medians to be more attractive than the original medians, and the museum's maintenance staff find maintaining the wetland medians as easy as maintaining other landscaped areas of the site. Most importantly for the museum's purposes, the natural stormwater control system provides an additional educational experience for museum visitors. The museum has placed interpretive signs explaining the benefits of swales and wetlands in improving water quality near the medians. The design is very popular with visitors and local residents, and people frequently comment on its aesthetic enhancement of the facility.

Contact: Rod McDowell, Vice President of Facilities, Oregon Museum of Science and Industry, OR, 503-797-4515, email: rod.mcdowell@omsi.edu.

StormFilter™ with CSF® Leaf Media Treatment System

Portland metropolitan area, OR 2
Population: 1,477,895
Area: 3.743 square miles

Highlight: Innovative technology that uses composted leaves to treat runoff is a space-conscious way to improve water quality.

Stormwater Management recycles autumn leaves or other filter media to make an effective, space-saving, in-line filter for polluted runoff. The firm contracts with the city of Portland to take approximately 50,000 cubic yards of leaves collected by the city each year. The firm then converts those leaves into approximately 5,000 cubic yards of compost, and transforms the compost into a filtering medium called CSF leaf media. When stormwater passes through the filter, pollutants are trapped or adsorbed to the rechargeable filter media.

Cylindrical cartridges about 20 inches high and 20 inches in diameter containing CSF or other media are the centerpiece of the StormFilter™ treatment system. The installer determines the number of cartridges necessary to treat the volume of water at the site. The type or combination of filtration media is also chosen based on site characteristics. For example, perlite or zeolite may be preferable in areas where residual nutrients may be a concern. The cartridges sit on the floor of concrete vaults of various sizes installed in the ground. Stormwater flows up from the base of the cartridges through the filter media and out through a center drainage tube to an underdrain manifold. The siphon-driven system prevents water from leaving the cartridge before the filtration occurs. The canisters require replacement as the pellets lose their filtering ability, but the CSF pellets themselves can then be reused as mulch or mixed with organic wastes to form compost for gardening.

Institutions throughout the Pacific Northwest have installed the StormFilter system with the CSF system in a variety of contexts. A McDonald's restaurant across the Columbia River in Vancouver, Washington, used a 6-foot by 12-foot vault to treat the runoff from its 1.3-acre site because it did not have space for grassy swales, detention ponds, or other water-quality control measures. Oregon City, Oregon, installed a 10-foot by 21-foot vault to clean runoff from the 7.5-acre site of its Metro South Waste Transfer Station. There, the StormFilter with CSF system augments an existing swale, which had failed to keep the sediments, oil, grease, and other contaminants generated by truck traffic, and more than 370,000 tons of waste transfer activity per year out of a nearby pond. At a third site in Hillsboro, Oregon, a joint effort by several municipal agencies resulted in the installation of a 12-foot by 100-foot vault to treat runoff from 70 acres of residential development and 3.9 acres of a five-lane arterial road. These are all early sites and Stormwater Management says that the technology and system design at newer sites has changed slightly but that the overall concept remains the same.

A big advantage of the StormFilter system is its small size, a characteristic particularly appealing to developers. The percentage of a site that is occupied by the StormFilter system, as evidenced by each of the three installations mentioned above, is remarkably low:

  • Vancouver, WA: 0.13 percent of site
  • Oregon City, OR: 0.064 percent of site
  • Hillsboro, OR: 0.037 percent of site

Monitoring by the United Sewerage Agency of Washington County at the Hillsboro site demonstrates the system's pollutant-removal effectiveness. The agency analyzed data from the first three storm seasons. The first flush of stormwater-the initial 1/4- or 1/2-inch of rainfall-is generally recognized as the flow of most concern, since it has the best opportunity to pick up the dust and other contaminants on parking lots and other previously dry surfaces. First-flush removal efficiencies for 10 pollutants of concern at the Hillsboro site were excellent. The monitoring found no first-flush removals rates of less than 60 percent in any given year, with three-year first-flush removal averages exceeding 80 percent for sediment indicators, chemical oxygen demand, chromium, iron, and zinc. Removal rates for the total flow-first flush and beyond-was less strong, but still impressive.

The StormFilter™ system is not inexpensive. Purchase and installation costs for a 6-foot by 12-foot unit range from $10,000 to $25,000; it can cost up to $100,000 for larger cast-in-place units. However, the small size of the system can provide compensating savings in land acquisition costs. In desirable commercial areas, land can cost $200,000 per acre or more. In those kinds of circumstances, where land to build swales, constructed wetlands, or wet ponds is unavailable or prohibitively expensive, the CSF system can provide a lower-cost alternative for water-quality control. Stormwater Management suggests that long-term effectiveness may be improved, however, by combining StormFilter with other temporary or permanent BMPs.

More than 400 StormFilter systems are currently in operation across the nation. Although the vast majority are in Oregon and Washington, units are also being used in Delaware, Vermont, and California. The largest installation to date is a 25-foot by 100-foot unit treating stormwater from the 18 miles of six-lane highway of the San Joaquin Hills Transportation Corridor project in Southern California.

Contacts: Janice Miller, Water Resources Program Manager, Clean Water Services, OR, 503-693-4493, email: millerj@cleanwaterservices.org. Penny Erickson, Operations Supervisor, Metro, OR, 503-797-1659. Loy Taylor, McDonald's Construction Project Manager, OR, 503-684-9334.

Additional Examples

Pipers Creek, Seattle, Washington3

To help restore Pipers Creek and bring back spawning salmon, the Pipers Creek Watershed Management Committee developed a watershed action plan for the creek in 1990. The plan outlines 39 Action Recommendations to protect and enhance the watershed. By setting these goals, the committee can monitor its progress. Some of the successful efforts to date include creating grassy swales and an in-channel detention area, revegetating the stream bank, improving in-stream habitat and fish passage, and plans for creating a model urban wetland and preventing sedimentation. The state is also treating the plan as a Total Maximum Daily Load (TMDL) for fecal coliform bacteria, thereby taking it off the 303(d) list.

Contact: Beth Miller, Watershed Interpretive Specialist, Carkeek Park Environmental Education Center, WA, 206-684-0877, email: beth.miller@ci.seattle.wa.us.

Princeton Village, Clackamas County, Oregon4

The developer used conservation design measures at this residential and office development including residences clustered as row houses, narrow driveways, access to public transit and a bike path, and shared parking facilities. A density transfer system under the county development ordinance allowed preservation of two wooded acres alongside a stream. Development began in 1993.

Contact: Transportation and Growth Management, Region 1, OR, 503-655-8521.

West Bend Village, Bend, Oregon5

West Bend Village consists of 88 detached single-family homes on a 22-acre site. Narrower streets and driveways reduces imperviousness while proximity to shopping, downtown, and schools encourages walking and bicycling. The developer made an effort to preserve trees, even curving the sidewalks in some cases. The development began in 1994.

Contact: Kris Reese, Sales and Marketing Manager, Tennant Developments, OR, 541-388-0086.

Bellevue, Washington6

Bellevue requires newly developing areas to include on-site stormwater management that provides protection for 24-hour, 100-year storm events.

Contact: Damon Diessner, Assistant Director, Environment Division, Utilities Department, Storm and Surface Water Division, City of Bellevue, WA, 425-452-4480, email: utilities@ci.bellevue.wa.us.

Promoting Public Education and Participation

Water Consortium's Mass Media Campaign

Puget Sound, WA 7
Population: 2.5 million (King County, Seattle, Bellevue, and Tacoma, Washington)
Area: 2,284 square miles

Highlight: Survey research enabled officials to target their audience for education and design a better program that helped raise public awareness and change behavior.

What are the most effective issues and means to reach, motivate, and educate Puget Sound citizens about specific actions that will protect the region's water resources? The water quality Consortium, a group focused on protecting Puget Sound's water quality that includes Washington Department of Ecology, Metro Water Pollution Control Division (now King County), Seattle Surface Water Management, King County Surface Water Management, and the cities of Bellevue and Tacoma asked this question in 1994. To find the answer, the consortium commissioned a public relations firm to survey residents and assess their understanding of and concern for water-quality issues.

The survey revealed that television and newspaper are the best media for reaching people, and that ads should focus on four human activities/behaviors: fertilizing lawns, maintaining cars to prevent fluid leaks, disposing of pet waste, and washing cars. With a better understanding of their target audience, the Water Quality Consortium hoped to encourage citizens to adopt water-quality-conscious behavior.

Guided by this research, the consortium implemented an ad campaign in January 1996. The ads themselves are quite original-a man walking across water pushing a fertilizer spreader and a car driving on water leaking oil. Each begins with a statement such as "When you're fertilizing the lawn, remember you're not just fertilizing the lawn," to remind the public that their actions affect water quality. The ads then explain how the activity leads to water pollution and why clean water is important. There are also specific tips outlining what residents can do to protect water quality.

After running the ads for approximately six months, the consortium surveyed the public again to assess the effectiveness of the advertising. These data showed that the advertising campaign was working. Awareness levels increased regarding the extent that washing cars, driving cars, fertilizing lawns, and pet waste contributed to the region's water pollution. Two of the consortium's advertisements elicited strong unaided recall, and one third of respondents who remembered the advertisements felt that they prompted some change their behavior. The results revealed a 15 percent increase in respondents citing water pollution as the most important environmental issue in the region in the year between the two surveys.

The consortium attributes the campaign's success to making an effort to understand their target audience beforehand. Surveys also facilitate evaluation of the program, enabling the consortium to make appropriate adjustments in the future. Furthermore, surveys provide the opportunity to collect useful information about public attitudes and perceptions. For example, the consortium found that residents are willing to invest in improving Puget Sound's water quality. A majority of the public is willing to pay $4 more per month through higher sewer rates or taxes, which was the highest amount offered in the survey.

The campaign and research cost $802,000, of which $500,000 came from a Washington Department of Ecology grant to King County and Metro, with the balance made up by the local governments. Due to the quality and content of the advertisements, the consortium also received a number of free ad spots for television, billboards, and newspapers. The consortium also ran several ads during prime times, such as the broadcast of professional sporting events.

The campaign reached a large population via multiple forums presented across the Puget Sound region and extending into Canada, Oregon, and the rest of Washington. The consortium continues to make advertising materials available to local governments and other public or nonprofit organizations in the region and around the world.

Contact: Annie Phillips, Washington State Department of Ecology, Watch Over Washington, 360-407-6408.

Naturescaping for Clean Rivers

Portland and Multnomah County, OR8
Population: 1,021,206
Area: 560 square miles

Highlight: Educating citizens about alternative gardening practices got people engaged in efforts to change their behavior and protect local waterbodies.

The Naturescaping for Clean Rivers program in the Portland metropolitan area has had long-lasting effects on individual behavior. The program started in 1995, when the Portland Bureau of Environmental Services and the East Multnomah Soil and Water Conservation District joined together to increase public participation in stormwater management. The goal of the program is twofold: to encourage individual homeowners to reduce the effect their yards have on water quality and quantity, and to increase the amount of native plantings and natural landscapes in those yards. The program works through a number of channels. The city has created a demonstration site at a middle school where citizens can stop by and learn more about stormwater- and habitat-conscious practices. The program has developed a workbook, descriptive booklet, informational brochure, door hanger, and other written materials. Program staff have made presentations to government agencies, environmental organizations, and other groups.

The program has also held residential workshops at local schools, libraries, and houses of worship. Participants obtain a workbook listing helpful hints and specific activities that help to achieve environmental ends such as increasing native plant and tree cover, increasing habitat for birds and other wildlife, and reducing pesticide and fertilizer use. The workshops also provide a forum to ask experts for information and advice, and to talk with other homeowners. Participants also receive a free native plant to get them started.

In 1996 approximately 220 area residents attended these workshops. During the spring and summer of the following year, Sharon Meross, a graduate student at Portland State University, conducted a telephone survey of 51 randomly selected workshop participants to measure the extent to which the workshops have changed their home landscaping practices. On average, the respondents had changed their activity in 7.6 of the 19 areas. Seventy-five percent added native plants to their yard or garden, and 87 percent of those who did so could clearly name at least one of the species added. One person planted over 70 native shrubs and wildflowers on his creekside lot. Fifty-one percent added deciduous or evergreen trees to their yard. Forty-nine percent reduced the quantity of lawn, and 68 percent of those individuals (one third of all those surveyed) had reduced their lawn coverage by 10 percent or greater.

Turning to pesticide and fertilizer use, the survey found that 53 percent started or increased composting and 43 percent used compost instead of fertilizer. Twenty-seven percent used less or no fertilizers, 25 percent used less or no fertilizer, and 24 percent used alternatives to pesticides.

The survey indicated that participation in the workshops brought the "naturescaping" message to those who did not attend, since 78 percent of those sampled had educated friends, neighbors, or relatives about at least one of the concepts presented at the workshops. Fifty-one percent of survey respondents had not participated in other community projects during the past year.

Although the numbers given above tell one side of the story, the surveyors' individual conversations with the participants tell another side. All but two of those contacted agreed to participate in the survey, and they expressed enthusiasm about the workshops and what they had been able to do since they attended.

Contact: Diane Hinton, Public Outreach Coordinator, Portland Bureau of Environmental Services, OR, 503-797-1842, email: naturescaping@yahoo.com.

Sound Car Washes

Kitsap County, WA9
Population: 230,000
Area: 396 square miles

Highlight: Low-tech BMPs collect runoff from charity car washes for proper discharge and provide an educational opportunity for the whole community.

Kitsap County, Washington, turned complaints from commercial car wash operations into an effective program for addressing water-quality issues associated with charity car washes. Commercial car washes expressed concern that charity-sponsored car washes did not have to meet requirements to recycle and treat water. Kitsap County responded by testing and promoting various BMPs for noncommercial car washes. The county seized this opportunity to educate people involved in charity car washes about urban runoff issues.

Noncommercial car washing is not a trivial matter when it comes to water quality. During a typical event, between 2,000 to 7,000 gallons of water are combined with soap, detergents, oil and grease, gasoline, heavy metals, and other pollutants. Water from these events typically runs into a storm drain that discharges directly to receiving waters. To address this problem, Kitsap County worked with charity groups and commercial car washes to research and test various BMPs for noncommercial car washes. Financial support for the first phase of Sound Car Washes came from the Puget Sound Water Quality Authority's Public Information and Education (PIE) Fund. Based on this testing, two easy-to-operate BMPs were selected: a mobile catch-basin insert with a sump pump and a vacuum/boom device known as the Bubble Buster.

The catch-basin insert captures runoff, allowing it to be pumped and discharged to either a sanitary sewer or a vegetated area. The installation of an insert costs approximately $65. The Bubble Buster, which looks like a modified Shop Vac, is placed down-gradient of the wash area to intercept runoff. The collected runoff is diverted to either a sanitary sewer or a vegetated area. The cost of a Bubble Busters ranges from $2,000 and $2,500. Both systems are available through the county for charity organizations to borrow. In some cases, locations that frequently host charity car washes have constructed their own catch-basin inserts.

Testing of the inserts and Bubble Buster occurred at 19 fund-raiser car washes held between April and August 1994, and again in April 1995. Approximately 130 students participated in these events and distributed over 300 copies of a brochure describing BMPs for car washes. The program also included public workshops on car wash BMPs, storm drains, and other water-quality issues. Students shared the knowledge gained from these workshops with customers and sponsors.

After the PIE grant phase, staffing became an issue. However, building off the program's strength as an educational tool, Kitsap County decided to incorporate it into the Surface and Stormwater Management Program's public education and outreach element. This has increased the number of participating car washes substantially. Approximately 50 car washes used the BMPs between April and August 1998. In addition, a part-time staff person leads all involved students through a training session that includes a video presentation on nonpoint pollution and its effects.

Through Sound Car Washes, Kitsap County is able to reach students, citizens, and businesses in one effort. To date, over 350 students and numerous citizens have participated in the program. Several local businesses that frequently host car washes have agreed to allow only events that go through the Sound Car Washes program. Since monitoring was not part of the program, water-quality improvements have not been documented. However, program coordinator Pat Kirschbaum says feedback from participants and customers has been very positive. Commercial car washes have also been supportive.

Several municipalities have looked to Kitsap County for information and advice on controlling runoff at charity car washes. The county has received calls from California, Hawaii, and several cities in Washington State; similar programs have been established in Bellevue and Tacoma, Washington.

Contact: Pat Kirschbaum, Public Outreach and Education Coordinator, Kitsap County Surface and Stormwater Management Program, WA, 360-337-7290, email: Sound Carwash@co.kitsap.wa.us..

Stormwater Education on the Internet

Washington State Department of Transportation10
Population: 4,866,692
Area: 66,581 square miles

Highlight: Putting the entire stormwater plan and all decision-making documents on the Web invites the public to participate in and support previously hidden state actions.

The Washington State Department of Transportation (WSDOT) recently developed a comprehensive stormwater program that improved openness and accountability, coordination with other agencies, and a commitment to whole-watershed restoration.

In the spring of 1997, WSDOT published its stormwater plan, detailing its efforts to coordinate watershed restoration projects, retrofit facilities for stormwater treatment, and conduct BMP research. WSDOT has made it a program goal to improve openness and outreach to the general public, and has developed a Web site that includes its entire stormwater plan (www.wsdot.wa.gov/eesc/environmental; click "water quality" and then on "water quality manuals and documents"). This document opens up the whole WSDOT decision-making process, including that for the stormwater program, to intelligent public scrutiny and participation. The high level of candor detail, and clarity (benefit-cost formulas and challenges are fully explained) of the WSDOT stormwater program report is in itself a major contribution to public participation.

Recognizing that a strong stormwater program needs a solid funding base, WSDOT obtained a funding program through the state legislature in 1996 that spelled out the responsibilities of both WSDOT and local governments, which receive about $1 million each year in stormwater utility fees from WSDOT. These moneys, along with ISTEA funding obtained in December 1996, funded six stormwater projects; five were retrofits for existing highway stormwater outfalls.

WSDOT has also taken on the challenge of removing the bias against environmental enhancements found in traditional cost-benefit calculations. Because it is difficult to assign numeric dollar values to the wide, but often intangible, range of benefits of environmental enhancements, environmentally conscious highway projects often result in a perceived unfavorable benefit-cost ratio. Through Washington State University, WSDOT and the Washington Transportation Center have sponsored research to include nonmarket benefits of protecting water resources (WSDOT Stormwater Management Plan, page 70).

Capital programs for new project construction comprise 85 percent of the state's highway budget, with 5 percent of typical project costs, or about $61 million annually, devoted to stormwater conveyance and treatment structures. Much of these funds have been committed to 39 potential retrofit projects to be started by the year 2000 if the stormwater program is fully funded. Taking the long view, environmental retrofits will potentially receive close to a billion dollars over 20 years.

Contact: Shari Schaftlein, Deputy Director of Environmental Services, WSDOT Environmental Affairs Office, Washington State Department of Transportation, WA, 360-705-7446, email: sschaft@wsdot.wa.gov. Ed Molash, Washington Management Program, Washington State Department of Transportation, WA, 360-705-7507.

Permit AreaNumber of OutfallsNumber of Major OutfallsNumber of Structural BMPsPercent with BMPs
South Puget Sound42121296.9%

Additional Examples

Salmon Corps, Columbia River Basin11

The Salmon Corps is comprised of more than 100, 18- to 25-year-olds, has completed over 315 watershed projects, and restored over 50 salmon habitats within the Columbia River Basin. Since 1994, they have released more than 6 million anadromous fish into these streams, which is a strong testament to the support of these projects from federal and state agencies. Most importantly, the Salmon Corps has successfully completed a wide variety of projects at one third to one half of the true market cost.

Contact: Christopher Shelley, Director of Education and Training, Salmon Corps, 503-249-0820, email: education@salmoncorps.org.

Wastemobile, King County, Washington12

To prevent discharges of household hazardous waste, the King County Solid Waste Department does public outreach and sends out the Wastemobile, a 5,000-square-foot vehicle, to collect household pollutants. When an education specialist was present, 30 percent of surveyed residents said they learned something new about household hazardous waste. The program stated in 1997.

Contact: Gerty Coleville, Program Analyst, Department of Natural Resources, King County Solid Waste Division, WA, 206-296-8459, email: gerty.coville@metrokc.gov.

Sound Gardening Program, Bellingham, Washington13

The Sound Gardening program, which started in 1994, uses demonstration gardens, workshops, classes, and presentations to promote ecologically friendly gardening with reduced chemical use. The program included workshops on integrated pest management and lawn care, along with self-guided tours of participating gardens. Environmental Resources informed the public about the program through brochures and media advertisements. An estimated 530 individuals were educated directly, and the agency received 50 pledges promising to reduce pesticide use.

Contact: Lisa Friend, Special Projects Coordinator, ReSources, Bellingham, WA, 360-733-8307, email: recycle@re-sources.org.

Salmon Challenge, King County, Washington14

Salmon Challenge is an interactive computer program targeted at fourth- to ninth-grade students. The game simulates the life cycle of a salmon with users altering inputs such as fertilizers, household chemicals, animal waste, and stormwater management. The computer can also interject with random natural events like floods. An animated salmon teaches how human activity can affect the life of a salmon and other aquatic organisms. Since 1990, approximately 1,200 copies of the program have been distributed. Pre- and post-program surveys have demonstrated increased knowledge of the issues affecting the region's water quality.

Contact: Donna Seligman, Department of Natural Resources, Water and Land Resources Division, King County, WA, 206-296-8494.

Controlling Construction Site Runoff

Setting Goals for Erosion Prevention

Eugene, OR15
Population: 118,000
Area: 38 square miles

Highlight: Taking an "outcome-based" approach to erosion prevention allows for flexibility while emphasizing water quality.

With 48 inches of average annual rainfall, stormwater management is not an unfamiliar issue in Eugene. However, before the early 1990s, efforts largely focused on flood control. In response to changes in the Clean Water Act, Eugene developed a comprehensive stormwater management plan. On November 10, 1994, Eugene became the first city of its size in the nation to be issued a municipal NPDES stormwater permit. Eugene considers its approach to be both proactive and practical, striving to reduce pollution through low-cost means such as land-use regulations, education, on-site pretreatment, and operational programs.

Rapid development and a push into more environmentally sensitive areas made construction sites a priority. To protect local waterways from construction-related activities, Eugene implemented the Erosion Prevention and Construction Site Management program in February 1997. By integrating regulation and enforcement with education and outreach, the Public Works Department was able to promote erosion prevention without antagonizing or excluding the construction community. The program requires all construction sites to employ, to the maximum feasible extent management practices that meet a specified set of outcomes including:

  • no deposit or discharge of sediment onto adjacent properties or into water features;

  • no degradation of water features due to the removal of vegetation;

  • no discharge or runoff containing construction-related contaminants into the city's stormwater system or related natural resources;

  • no deposit of construction-related material exceeding one-half cubic foot for every 1,000 square feet of lot size onto public rights-of-way and private streets, and into the city's stormwater system and related natural resources.

Taking an "outcome-based" approach allows contractors to choose the erosion prevention and construction site management practices best suited for a site. Eugene considers all approaches practicable unless implementation costs would outweigh the benefits of maintaining water quality. Costs are considered to outweigh benefits if they exceed $0.50 per square foot of disturbed area. The city provides assistance when receiving a permit application, reviewing a plan, or conducting an inspection.

The program addresses sites based on size, whether they are a commercial development or a single-family or duplex dwelling, and whether or not they are in a sensitive area. Therefore, some sites may not require a permit even though all sites are required to meet mandated outcomes. Permits are required for all sites that disturb more than 500 square feet of soil and are in sensitive areas such as steep terrain, highly erodable soil, or near an open waterway or wetlands. Permits are also needed for sites 5 acres or greater regardless of location.

An erosion prevention plan is required under the permit process. Plans must identify potential water-quality impacts from construction activities and specify actions to address them. Content is up to the contractor, but commercial plans must be designed by a state licensed or certified professional. The process is simpler for construction sites consisting of one single-family or one duplex dwelling.

BMPs are not based on a one-size-fits-all formula, but instead are chosen to address potential problems specific to a site. City personnel such as erosion prevention specialist Sarah Medary help contractors think about the land they are disturbing and how to choose the best options for addressing erosion at their site. Using this approach, inspections become an opportunity to educate contractors and improve site plans instead of a process for shutting down operations and levying fines. Nonetheless, outcomes must be met and the erosion permit approved before any other construction permits will be granted.

Eugene determines permit fees based on the type of permit and size of the disturbance. Fees cover the cost of the program but can be supplemented by the city's stormwater fund. The program is designed to be self-supporting, but the city has not verified this status and some staff feel that it has fallen short of this goal.

Since the program is relatively new, opportunities to evaluate its effectiveness have been limited. Collection of baseline data would have facilitated before and after comparisons. It is likely that effectiveness will remain in question as long as there is no formal measuring of the program's impact on water quality.

Nonetheless, early signs are good. Increasing awareness has led to better plans and site management. In addition, the city received fewer calls requesting stormwater system maintenance, although the amount of money saved has not been calculated. Streets also appear to be cleaner and freer of sediment, which Medary attributes to more contractors including street cleaning as a BMP. Results of an informal questionnaire related to the first year of the program indicate its increased acceptance.

Compliance has been good and inspections have led to fewer fines and penalties. To date, Public Works personnel have issued 450 erosion prevention permits, completed 621 site inspections, and responded to 150 complaints. Of the 127 complaints in the first year of the program, 90 percent were filed against residential properties not requiring a permit. Some questionnaire respondents felt that the program should be more active in the field, inspecting and issuing citations. In addition, due to the administrative success of the program, Eugene became the first municipality in the state to be granted authority to administer state construction permits, helping to simplify the overall process.

Contact: Molly Ritter, Erosion Prevention Specialist, Public Works Engineering, Eugene Erosion Prevention Construction Site Management Program, Eugene, OR, 541-682-8495, email: molly.k.ritter@ci.eugene.or.us.

Training and Certification Program

Washington State Department of Transportation 16
Population: 4,866,692
Area: 66, 581 square miles

Highlight: Providing training and certification improves attitudes toward and use of erosion control BMPs at highway construction sites.

Temporary erosion and sediment control at construction sites is a key component of the Washington State Department of Transportation's (WSDOT) stormwater management program. Site investigations revealed serious erosion problems that could have been avoided if the right combination of BMPs had been implemented. Believing that erosion and sediment control could be greatly improved through education, training, and interdepartmental coordination, the agency implemented the Construction Site Erosion and Spill Prevention training program.

Begun in 1994 as a series of short classes covering general topics designed for agency personnel, by 1996, the program had evolved into a two-day course held 10 to 12 times per year under the direction of a full-time coordinator. The training program focuses on field personnel, with the goal of providing practical information using a hands-on approach.

In 1997, a special provision was added to the state's standard construction specifications that required contractors to designate a site's Erosion and Spill Control Lead. This certified person must be available to administer erosion and spill control programs at construction sites that are adjacent to wetlands, shorelines, or other sensitive areas. Certification is obtained by participating in WSDOT's training course.

The new provision attracted members of the contracting community looking to be certified, as well as representatives from other agencies that deal with erosion and sediment control issues and members of the landscaping/hydroseeding community. A number of people use certification to market themselves as subcontractors. This has the positive result of making the erosion and sediment control requirements more amenable to smaller contractors who claim it is difficult to have an in-house certified lead. By teaching and demonstrating proper erosion and sediment control techniques, the training program helps contractors avoid problems, thereby reducing the need for certified persons on-site.

Coordinator David Jenkins designed the training sessions to be interactive, with the objective of providing tools for implementing an effective-program and addressing problems as they arise. By emphasizing education, WSDOT avoids a heavy-handed approach that some contractors find antagonistic. Jenkins explains that part of the program's strength stems from its emphasis on examining why erosion is occurring, identifying what is not working, and then working together to fix the problem in a timely and cost-effective manner. He says that contractors have been receptive to this approach because they feel acknowledged and involved in the decision-making process. Jenkins also sees the classes as an opportunity to bring different experiences and points of view together in a constructive environment, away from the construction site. While this diversity represents an excellent learning opportunity, it poses perhaps the biggest challenge to program coordinators: integrating the interests of all participants.

The course exposes contractors to new strategies and techniques, and demonstrates the best approaches for a variety of circumstances. State Erosion Control Inspector Larry Worcester say that raising awareness and putting people on the same page makes his job easier and more efficient. Worcester credits the training program for the relatively low turbidity in water samples collected downstream from the State Highway 18 project between Auburn and North Bend.

While WSDOT's sites are not problem-free, Jenkins has seen a noticeable change since the program's inception. In particular, he notes that contractors are being more proactive in addressing erosion and sediment control. For example, it used to be common for huge gullies to form down bridge embankments during construction. Jenkins now sees contractors preventing erosion by connecting temporary pipes to catchbasinss, or using pipe-slope drains to transport stormwater down the embankment. Contractors are also becoming increasingly aware of the economic advantages of being good stewards. A powerful incentive lies in the fact that highway construction sites are often under continual observation by the public.

WSDOT has trained approximately 1,000 people, and so far, feedback has been positive. In several cases, contractors applied what they had learned to an issue at their site before the class was over. The program has also been successful at reaching other members of the road and highway construction community. Since most local road maintenance operations use the state's contract specifications, more and more cities and counties are requiring their personnel to take the course. Additionally, transportation agencies in Oregon, California, and Idaho are interested in adopting similar training programs as part of their stormwater management efforts.

Contact: Richard Tveten, Statewide Erosion Control Coordinator, Washington State Department of Transportation, 360-570-6648, email: TvetenR@wsdot.wa.gov.

Additional Examples

Andover Park, Beaverton, Oregon17

To comply with city requirements that wetlands and trees be preserved, the developer clustered apartments in an area previously logged and saved 60 percent of existing mature fir trees at this 17.6-acre forested site. Subsequent analysis demonstrated that tree preservation cost less than typical site clearing and relandscaping. GLS began the project in 1987.

Contact: GSL Properties, Portland, OR, 503-224-2554.

Construction Site Stormwater Management, Bellevue, Washington18

Bellevue requires developers to prepare a temporary erosion and sedimentation control plan for any construction requiring either a stormwater detention facility or a clearing and grading permit.

Contact: Damon Diessner, Assistant Director, Environment Division, Utilities Department, Storm and Surface Water Division, City of Bellevue, WA, 425-452-4480, email: utilities@ci.bellevue.wa.us.

Detecting and Eliminating Improper or Illegal Connections and Discharges

Sanitary Surveys

Mason County, WA19
Population: 49,477
Area: 961 square miles

Highlight: By identifying failing septic systems and requiring maintenance or repairs, an inspection program helps reopen valuable shellfish beds.

On-site sewage systems are a consistent and significant threat to water quality in the Lower Hood Canal, Oakland Bay, and Totten and Little Skookum bays, all tributaries to Puget Sound. Mason County, home to some of the richest shellfish tidelands in the country, has more than 16,000 on-site sewage systems and no municipal sewer system. In 1987 and 1993, pollution from homes and farms led to the closure of shellfish harvesting on a combined 1,590 acres of tidelands at the end of Lower Hood Canal; 1,260 acres of North Bay tidelands were closed in 1991.

Mason County, located in the southwest corner of Puget Sound, has a full- time population of about 50,000. Its popularity as a bedroom community for Seattle and Tacoma, as well as a recreation destination, has helped generate the second-highest growth rate in Washington. Since the 1990 Census, the population has grown 19.62 percent at an annual rate of 2.2 percent. Due to its popular outdoor recreational resources, the population during summer weekends approaches 100,000.

Dramatic changes in population and land use over the past few decades contributed to poor water quality in the region's estuaries. Officials recognized failing on-site sewage systems as a significant source of water pollution. In response, the county signed a consent order with the Washington Department of Ecology in 1993, agreeing to step up the county's management of them.

In 1992, a newly strengthened state law20 provided an opportunity for Mason County to address the issue by establishing clean water districts, which gave the county the ability to generate dedicated revenues for local water-quality needs and granted it legal authority to conduct inspections. Inspections of on-site sewage systems or "sanitary surveys" around the region's shellfish waters became the core of the county's efforts to protect the estuaries.

The county created clean water districts either voluntarily or as a requirement by the state, with state and local shellfish growers providing some financial support for the program. In addition, the county assessed fees to property owners in the two districts that ranged from $35 to $52 per year in the period from 1993 to 1996. Properties adjacent to tidelands in the Lower Hood Canal district were assessed an additional $26 because of less financial support and a larger coverage area. (Some residents felt that the fees should have been distributed throughout the county instead of focusing on the districts, which only make up about one quarter of the county's population.)

Between 1991 and 1995, the county inspected over 4,500 on-site sewage systems in targeted watersheds. Inspectors visually inspect the system and, if warranted, conduct a dye test and collect water samples for fecal coliform analysis. The table below is a summary of the results to date.

Most of the failed systems required only minor, inexpensive corrections such as repairing a drainfield or pumping a septic tank. It is clearly easier and cheaper to detect problems early, before expensive repairs are needed. However, several systems did require more extensive work. To help reduce costs, the state Department of Ecology provided low-interest loans to property owners.

Originally, clean water districts provided the legal authority to obtain access to properties and perform sanitary surveys. However, a subsequent state supreme court decision reduced this authority, restricting government access to private properties. Shielded by this law, property owners denied inspections of approximately 400 systems as of 1996. To encourage cooperation, the county sent letters to these property owners stating that a denial of inspection could lead to a notice of noncooperation placed on the property deed. This helped stimulate responses from a majority of the remaining properties in Lower Hood Canal.

Mason County found dye testing to be simple, affordable, and reliable, making it an appealing assessment tool. However, officials there warn that the information provided should be weighed against other variables such as type of treatment system. While dye tests are affordable, they still cost money-Mason County estimates a cost of $95 per visual inspection, $290 per dye test survey, and $285 to oversee the repair process.

Water-quality sampling has documented that efforts such as sanitary surveys help improve shellfish bed conditions. Donald Melvin, environmental specialist for the state's shellfish restoration program, feels that sanitary surveys are a model approach that he would like to see applied elsewhere.

The benefits of protecting and restoring the shellfish beds and scenic resources are invaluable. The region has the highest amount of recreational shellfish harvesting in the state, and commercial shellfishing is a significant proportion of the local economy, providing the second-highest number of jobs and contributing to the tourism industry. Puget Sound is currently the nation's leading oyster producer. The value of the shellfish beds in the region has grown tenfold in the last 10 years and is projected to be worth $20 million in the year 2000. Shellfish growers are pleased with the outcomes of the program, and have been active at promoting water-quality improvements in Puget Sound.

Sanitary surveys play an important role in protecting these valuable natural resources. Through this program, homeowners have fixed or replaced 100 percent of the identified failed systems in the Totten-Little Skookum watershed, and 87 percent of the identified failed systems in the Lower Hood Canal watershed to date. As a result, water quality in the Little Skookum continues to be good, parts of North Bay have been upgraded, and the Department of Health has reopened over 900 acres of shellfish beds in Lower Hood Canal.

Contact: Pam Denton, Environmental Health Department, Mason County, WA, 360-427-9670.

WatershedSurvey DatesNumber TestedNear Shore Number FailedPercentage FailedNumber TestedUpland Number FailedPercentage Failed
North Bay1991–19922005025751013
Totten-Little Skookum1993–19954947014651274
Lower Hood Cannal1994–1996141717512.33,3803088

Illicit Discharges Elimination Program

Portland metropolitan area, OR21
Population: 1,700,000 (metro area)
Area: 3,743 square miles

Highlight: Developing a comprehensive program that addresses illicit or improper discharges from industry, city bureaus, and other sources reduces pollutant loads.

Portland addresses the issue of non-stormwater discharges by identifying illicit connections and preventing discharges from known runoff generating activities. In taking this approach, the Bureau of Environmental Services has corrected 60 to 70 illegal connections or ongoing process discharges in five years, and helped implement long-term strategies to prevent countless others. The city estimates an additional 60 to 120 illegal connections were detected through referrals and related programs.

Portland is required by permit to identify and eliminate illicit connections and discharges. In response, the city implemented the Illicit Discharge Elimination Program (IDEP) in 1994. IDEP approaches the issue from three angles: 1) monitor and assess the stormwater system to identify unknown sources; 2) review plans of new and existing industrial facilities under the city's industrial pretreatment program to prevent future illicit discharges; and 3) work with known potential sources of non-stormwater runoff to reduce improper discharges. In addition, the city expanded its 24-hour pretreatment program spill hot line to include stormwater issues, and encouraged the public to help identify and report improper discharges or spills.

The city monitors between 90 and 100 priority outfalls during the dry season, and samples outfalls three or four times per summer, on average, for pollution indicators including fecal coliform, residual chlorine, conductivity, pH, and temperature. The top 15 to 20 are sampled more often. Staff credit the bureau's commitment to monitoring as a critical component of the program's overall effectiveness.

If an illicit discharge is suspected, bureau staff collects additional samples to help identify the source. By comparing monitoring results with a database of connections to the system and what activities they perform, Portland has been successful at finding a source for nearly all detected discharges. Once found, the case is forwarded to the appropriate city agency, which then works with the discharger to correct the problem. Corrective actions have typically included repairing leaks, installing closed-loop air-conditioning systems, adopting better management practices, relocating operations, and installing wastewater treatment technologies.

To prevent improper discharges, the industrial stormwater staff reviews building plans and conducts site visits at commercial and industrial facilities. During site visits, inspectors verify connections to the stormwater and sanitary sewers, identify where they drain to, determine whether an NPDES permit is required, and educate the owner/operator about improper discharges. Inspectors also check floor drains and other potential discharge pathways for compliance.

The hot line receives approximately 600 calls per year regarding pollution complaints, industrial information, spills, septic discharges, and agency referrals. During the 1996/1997 fiscal year, 68 of these calls resulted in incidental stormwater discharge resolutions. To inform the public about the program, all pretreatment industries are required to post signs; flyers and cards are included in materials sent out in response to BES inquiries. Still, local interests believe that more should be done to increase knowledge of IDEP and the hot line.

Progress has also been made at preventing improper discharges from municipal operations by working with the city's water and fire departments, and its parks bureaus. With Environmental Service's help, the Fire Bureau has implemented BMPs at their training facility to prevent foam wastes from entering storm sewers, and transferred cleaning operations to a general service facility with BMPs and a wastewater treatment system in place. In addition, the bureau has dye tested their facilities, identified potential and existing discharge points, and set up strategies to prevent inappropriate discharges. The Water Bureau developed procedures for dechlorinating all water used to flush and clean storage tanks and distribution lines, and the Parks Bureau redirected pool water discharges to sanitary sewers. Environmental Services is still developing its programs targeting nonmunicipal runoff generators. Partnerships have been established with automotive trade groups, the Multnomah County Health Department, and the dental and medical community.

The program is backed by a city code22 that prohibits any process wastewater discharge to the stormwater system. At this point, there is no formal mechanism for enforcing the code. Therefore, the city is limited to taking legal action through the district attorney's office. To avoid this cumbersome process, the city tries to establish voluntary efforts to prevent non-stormwater discharges. According to Environmental Services staff, response to this approach has been good. On the other hand, they realize that stronger enforcement will be needed as the city addresses operations with more challenging cost and feasibility issues. For example, the city has been working to implement BMPs for commercial mobile washing operations. Unfortunately, cooperation has been limited since the economy of scale makes runoff prevention disproportionately expensive for these activities. Without enforcement, Environmental Program supervisor Kelly Hendryx believes that these operations will continue to be a source of polluted runoff.

Consultants for the city estimated pollution reduction benefits from the IDEP based on four source categories: illicit sanitary connections, washwater discharges, accidental spills, and erosion/sedimentation problems. Estimated annual loads for various pollutants from a single discharge event are listed below:*

Illicit Sanitary ConnectionsWashwater DischargesAccidental SpillsErosion/Sedimentation
  • TSS – 250 lbs
  • BOD – 250 lbs
  • total N – 40 lbs
  • Total P – 10 lbs
  • TSS – 100 lbs
  • BOD – 80 lbs
  • Total oil and grease – 4 lbs
  • Copper – 0.04 lbs
  • Lead – 0.01 lbs
  • Zinc – 0.14 lbs
  • Diesel Fuel – 400 lbs
  • TSS – 1630 lbs
*The estimated annual loads were calculated based on assumed water-quality and flow from a single illicit connection or other improper discharges.

Contact: John McGregor, Environmental Specialist, Water Pollution Control Laboratory, City of Portland Bureau of Environmental Services, OR, 503-823-7767, email: johnm@bes.ci.portland.or.us.

Additional Examples

Illicit Connection and Discharge Detection and Elimination Program, King County, Washington23

King County Department of Natural Resources uses a tiered approach to identify illicit discharges and connections. First, inspections can be performed at businesses if a potential problem is noted or reported. Second, the public can report a prob- lem through a complaint hot line. Third, city technicians can inspect the facility for problems during other official visits. King County also has an incentive program. If a facility implements a stormwater pollution prevention plan and is in compliance with code, they become eligible to be classified as a Business for Clean Water.

Contact: Kate Rhodes, Department of Natural Resources, Water and Land Resources Division, King County, WA, 206-296-8046.

Implementing Pollution Prevention for Municipal Operations

Grounds Maintenance Program

Eugene, OR24
Population: 118,000
Area: 38 square miles

Highlight: A well-received IPM program keeps city parks and recreation areas beautiful while preventing pollution and saving money.

Pragmatism is the underlying motivation behind the integrated pest manage- ment (IPM) program used by the city of Eugene, Oregon, at its public parks and recreation areas. Timothy Rhay is the turf and grounds supervisor for the city. He recalls first becoming aware of IPM at a presentation he was forced to attend in 1980. He expected to hear from a group of environmental radicals whose presentation would be a "waste of time." But once the speaker explained the logic of IPM, he asked himself, "Where has this been all my life?" When Rhay returned to Eugene, he began an IPM program-one of the first municipal programs in the nation-and became an expert in the field himself.

IPM dates back to the early 1920s, when cotton farmers turned to alternatives to pesticides as the first defense against boll weevils for economic reasons: Reliance on pesticides to achieve the degree of control necessary was too expensive. Eugene's program relies on a variety of IPM approaches, including water blasting (to dislodge aphids), mulching, competitive plantings, insecticidal soaps, and limited use of pesticides when necessary. Perhaps the simplest concept is establishing higher toleration levels for pests and only taking action if infestation exceeds those thresholds. For example, the city's policy is that dandelions are not a problem in many park situations and therefore nothing needs to be done about them.

The turf on athletic fields, however, is one special area, since the heavier use makes it more prone to invasion by weeds. Nonetheless, Eugene has only sprayed its athletic fields with herbicides three times in the last 15 years-and then only on certain parts. On these fields, the city uses a variety of cultural and mechanical practices: aeration, top dressing, adjustment of mowing height, regular fertilization from appropriate sources, and correct watering. This kind of attention keeps grass, rather than weeds, growing, thereby avoiding herbicides. The rose garden, which was maintained for seven years without fungicide treatment, remains beautiful enough to serve as a backdrop for local television shows. However, recent weather conditions have increased fungal disease in the area requiring the use of some fungicide to control mildew, black spot, and rust.

This kind of attention does requires more time, but the program can afford to spend more time on athletic fields and gardens because of savings elsewhere. Eugene's pesticide usage has dropped by approximately 75 percent in the first few years of the program, with additional reductions since then. Although Rhay has no overall estimate of cost savings since the implementation of the IPM program, he remains convinced that IPM saves the city money. No one has suggested that the city move away from IPM.

The citizens of Eugene continue to offer strong support for the program. The city is willing to use more pesticides when necessary, but almost never hears citizen requests to do so. Of the three or four citizen complaints that Rhay can remember, one came to the attention of the city council and Rhay's supervisor, who was not familiar with IPM procedures. Rhay asked the supervisor to inspect the athletic fields and other park land. After taking a look, the supervisor told Rhay to keep the IPM program in place and the council made no changes.

One key to success, Eugene found, is giving the field crews a sense of involvement in decision making. Because Eugene has done this, its field crews have no desire to move away from IPM. It also helped to implement IPM gradually by focusing on one or a few pest problems at a time. Once the staff has created and tested effective control strategies for the situations in which chemical usage is greatest or the pests are most problematic, the program can move on to other pest control problems. Rhay remains convinced that "virtually any pest control program can be done through IPM."

Contact: Timothy Rhay, Parks Maintenance Manager, Parks and Open Space Division, Public Works, OR, 541-682-4800, email: tim.r.rhay@ci.eugene.or.us.

Reducing Impervious Cover at School

Olympia, WA 25
Population: 39,070
Area: 16 square miles

Highlight: An infiltration trench covered with a pervious parking surface virtually eliminated a nuisance flooding problem without reducing parking capacity.

Frequent flooding of Henderson Field at Olympia High School provided the perfect opportunity for the city of Olympia, Washington, to demonstrate technology for reducing impervious surfaces and controlling stormwater runoff.

Olympia recognized that impervious surfaces contribute significantly to increases in stormwater runoff and its associated problems. Based on current trends, the city estimated an increase from 14 to 29 percent imperviousness in three local drainage basins. At full development (80 percent of buildout) the resulting amount of impervious cover in these basins would generate enough runoff to flood Olympia 2 feet deep, or create a 62-acre, 100-foot deep lake. An impervious surface reduction study performed by the city found vehicle-oriented pavement to be the greatest opportunity for impervious surface reduction, particularly in higher density areas. The study recommended, as one strategy, the use of pavers (concrete grid and modular pavement with spaces filled with pervious materials such as sod, sand, or gravel) and other pervious surfaces for certain transportation related surfaces.

Historically, Henderson Field often floods after even relatively minor precipitation events. These conditions prevented use of the field and posed a particular nuisance during soccer season. The city believed it could correct the problem by constructing a stormwater infiltration system as part of the parking area while retaining the necessary parking capacity. In addition to preventing runoff from collecting on the field, the infiltration system would likely help to treat stormwater runoff as well.

The infiltration system has three main components: a lateral trench filled with sandy gravel that provides infiltration and retention; a plastic honeycomb support unit that bears the weight of vehicular loads; and a vegetated surface cover that helps stabilize the system and prevent soil erosion. The plastic honeycomb support unit, called Geoweb", produced by Presto Products Company, allows rain to infiltrate while minimizing compaction. The overall volume of the system is 4,000 cubic feet (cf) with an estimated dry retention capacity of approximately 1,700 cf. While existing soil moisture may affect retention, actual capacity may be greater since runoff infiltrating from the system into surrounding soils was not accounted for.

So far, monitoring has demonstrated that the system is working. Data collected between October 1995 and January 1996 by Olympia High School students and city personnel showed that the system has reduced flooding of Henderson Field. While the city did not collect pre-construction data, anecdotal information from neighbors and school staff supports the monitoring results. Students found flooding on only six of the 48 days that they visited the site. Precipitation occurred on 34 of these days, with an average daily rainfall of 0.48 inches throughout the monitoring period. Weekly inspection of the site and groundwater gauging supported the students' findings. According to study coordinator Cedar Wells, who frequently visits the site, the trench is performing well and has prevented flooding from parking lot runoff. Observed ponding usually occurred on days after heavy rainfall events or several consecutive days of precipitation, which the city attributes to slow infiltration on the field itself. Most important, Henderson Field, which use to flood periodically, is now usable for almost all events.

The system has withstood vehicular traffic, and compaction of the pervious backfill has not been a problem. While a control plot revealed some wear and tear on the turf, the city has not observed major damage. Nonetheless, maintenance is required in terms of mowing and irrigation during dry months to keep the system in good working condition and appearance. One possible long-term issue is gradual clogging of poor spaces by silt and grit. However, periodic replacement of the sod could help alleviate this problem. In addition, while the system should help treat stormwater runoff, there is a potential for pollutants to reach groundwater. The city notes that it is also important to recognize access issues raised in the Americans with Disabilities Act (ADA).

The initial installation cost of pervious alternatives is usually thought to be two to four times more expensive than asphalt. However, the costs are much closer at Henderson Field. The total cost of the infiltration strip was $23,379, which included installation, testing and monitoring, public involvement and education materials, design/report labor, and monitoring labor. The unit cost for a paved surface was estimated to be $48 per square yard versus $61.50 per square yard for the infiltration strip. The costs would actually be closer if the infiltration strip had not required replacement sod after the original sod died due to lack of watering.

Construction, operation, and maintenance costs alone do not necessarily accurately compare the value of one system over the other. There are many benefits associated with the infiltration strip that the city did not quantify. In addition to reducing flooding to the athletic field, the infiltration strip is also likely to improve surface water quality. Officials are pleased that it continues to provide a forum for Olympia residents to become more familiar with alternatives to conventional road paving surfaces. Other benefits to alternative pavement include:

  • increasing safety by eliminating the potential for water buildup on impervious road surfaces that can cause hydroplaning, skidding, or road flooding hazards;

  • improving aesthetics by eliminating the need for curbs and gutters;

  • preventing warming of ambient air temperature caused by asphalt;

  • providing a quieter driving surface.

Contact: Cedar Bouta, Study Coordinator, City of Olympia Public Works Department, WA, 360-753-8454, email: cbouta@ci.olympia.wa.us.

Additional Examples

Stormwater System Cleaning, Bellevue, Washington26

Cleaning of inlet pumps and catchbasinss reduces runoff concentrations of lead and total solids by 10 to 25 percent and oxygen-demanding substances by 5 to 10 percent as well as reducing nutrient and zinc concentrations. Cleanup of creeks and sloughs increased canoeing activity and use of park trails.

Contact: Damon Diessner, Assistant Director, Environment Division, Utilities Department, Storm and Surface Water Division, City of Bellevue, WA, 425-452-4480, email: utilities@ci.bellevue.wa.us.


1. Liptan T., and C. Brown, A Cost Comparison of Conventional and Water-Quality-Based Stormwater Design, unpublished manuscript, pp. 1–3; Thompson, J. W., "Let That Soak In," Landscape Architecture, November 1996, pp. 60–63; Portland Metro, City of Portland Bureau of Environmental Services & Unified Sewerage Agency of Washington County, The 1996 Stormwater Design Award Competition Handbook, 1997.

2. Coffey, L. T., "Portland Firm Turns Over a New Leaf," Daily Journal of Commerce (Seattle), November 19, 1996, pp. 3, 6; Forney, D., "Innovative System Installed at Lighthouse Plaza to Protect Creek," Cape Gazette, November 15–21, 1996, p. 14; Stormwater Management, Three Year Performance Summary, 185th Avenue, Hillsboro, Oregon, undated (data compiled and analyzed by the Unified Sewerage Agency of Washington County); Portland Metro, City of Portland Bureau of Environmental Services & Unified Sewerage Agency of Washington County, The 1996 Stormwater Design Award Competition Handbook, 1997.

3. Terrene Institute, Nonpoint Source News-Notes, Issue No. 48; Pipers Creek Watershed Management Committee, Pipers Creek Watershed Action Plan 1998 Status Reprot, draft, July, 1998.

4. Livable Oregon & the Smart Development Project, Princeton Village, undated.

5. Livable Oregon & the Smart Development Project, West Bend Village, undated.

6. U.S. Environmental Protection Agency, President Clinton's Clean Water Initiative: Analysis of Benefits and Costs, 800-R-94-002, Office of Water, Washington D.C., March 1994, p.18.

7. Elgin DDB and Edmunds Research Services, October 1996, The water-quality Consortium Public Awareness Study Summary Report; Elgin Syferd DDB Needham, May 1995, The water-quality Consortium Research Summary Report; Getchell, M., Public Information Officer, Water Division, Washington Department of Ecology, personal communication, September 14, 1998.

8. Meross, S., Naturescaping for Clean Rivers Survey Report, unpublished report, July 22, 1997; City of Portland Stormwater Program, Public Participation Action Plan for Fiscal Years 1995–96 and 1996–97, City of Portland Bureau of Environmental Services, March 1996; Portland Bureau of Environmental Services and East Multnomah Soil & Water Conservation District, "Naturescaping for Clean Rivers," pamphlet, April 1996.

9. Kirschbaum, P., Program Coordinator, Sound Car Washes, Kitsap County SSWM Program, personal communications, August 4, 1998 and September 9, 1998; Puget Sound water-quality Authority, Promoting Stewardship of Puget Sound: More PIE Success Stories, April 1996.

10. Washington State Department of Transportation, Stormwater Management Plan, 1997; Cook, J., SAIC, personal communication, spring 1997.

11. American Rivers, 1997 Urban Hometown River Awards factsheets, 1997; Earth Conservation Corps, Salmons Corps: Good Science, Good Sense, Good Partnerships, Good Results, factsheet, 1998.

12. U.S. Environmental Protection Agency, Guidance Specifying Management Measured for Sources of Nonpoint Pollution in Coastal Waters, 840-B-92-002, January 1993, pp. 4–127; Cunningham Environmental Consulting, Inc., Hazardous Wastemobile Education Program Telephone Survey Results, Bainbridge Island, Was; July 1997.

13. Sound Gardening Program Final Report, 1998.

14. Seligman, D., King County Department of Metropolitan Services, personal communication, August, 1998.

15. Medary, S., Erosion Prevention Specialist, City of Eugene Public Works Department, personal communications, August 13, 1998 and September 23, 1998; City of Eugene Public Works-Engineering, Erosion Prevention Program Fact Sheets, 1997; City of Eugene Public Works Stormwater Management Program, 1995. Stormwater/Wetland Progress Report Year One: January– December, 1994; City of Eugene Public Works Stormwater Management Program, "Construction Site Program Prevents Pollution," Stormwater Connections, Winter Edition, 1997.

16. Jenkins, D., Erosion and Sediment Control Training Program Coordinator, Washington State Department of Transportation, personal communication, August 10, 1998; Washington State Department of Transportation, Annual Report for the Cedar-Green, Island-Snohomish, and South Puget Sound NPDES MS4 Permit Areas, 1996–1997; Washington State Department of Transportation, 1995, Highway Runoff Manual; Washington State Department of Transportation, Water-quality Temporary Erosion and Sediment Control Program, August 10, 1998; http://www.wsdot.wa.gov/eesc/environmental/WQTESC.htm; Worcester, L., Street Inspector Erosion Control, Washington State Department of Transportation, personal communications, August 19, 1998.

17. Bookout, L. et al, Value by Design: Landscape, Site Planning and Amenities, Urban Land Institute, 1994, pp. 68–75.

18. U.S. Environmental Protection Agency, Guidance Specifying Management Measured for Sources of Nonpoint Pollution in Coastal Waters, 840-B-92-002, January 1993, pp. 4–597.

19. Banner, B., Director of Health Services, Mason County, personal communication, September 22, 1998; Denton, P., Environmental Health Specialist, Mason County Environmental Health Department, personal communication, August 5, 1998; Glasoe, S., 1996, "Sanitary Surveys in Mason County," Puget Sound Notes, No. 39; Hindle, Susanne (editor), 1996, "Water quality Protection That Gets Results," Sound Waves, vol. 11, no. 2; Hindle, Susanne (editor), 1996, "News From Around Puget Sound," Sound Waves, vol. 11, no. 5; Hupp, J., Assistant Director, Mason County Economic Development Council, personal communication, September 21, 1998; Mason County Department of Emergency Services, April 1998; http://des. co.mason.wa.us/; Melvin, D., Environmental Specialist, Washington Health Department, Office of Shellfish Programs, personal communication, September 15, 1998; Tompkins, M., Program Manager, Washington State Department of Health, personal communications, September 15, 1998.

20. In 1992 the Washington Legislature amended the law for shellfish protection districts (Chapter 90.72 RCW) to give counties greater flexibility for establishing and funding programs to control diffuse sources of pollution to coastal areas, referred to as clean water districts in Mason County.

21. City of Portland, National Pollutant Discharge Elimination System Municipal Separate Storm Sewer System Discharge Permit Annual Compliance Report No. 2: Fiscal Year 1996-97, September 1997; Harper, C., Water Resources Planner, Woodward-Clyde Consultants, personal communication, September 28, 1998; Hendryx, K., Environmental Program Supervisor, City of Portland Bureau of Environmental Services, personal communication, August 21, 1998; Hottenroth, D., Environmental Specialist, City of Portland Bureau of Environmental Services, personal communication, September 4, 1998; Lipton, T., City of Portland Bureau of Environmental Services, personal communication, September 30, 1998; McGreggor, J., IDEP Program Supervisor, City of Portland Bureau of Environmental Services, personal communication, August 20, 1998; Woodward-Clyde Consultants, Illicit Discharge Elimination Program (IDEP) Report, January 1997.

22. Municipal Ordinance 17.39.

23. Rhodes, K., King County, personal communication, August 18, 1998.

24. Rhay, T., "Avoid IPM Implementation Pitfalls," in A. R. Leslie, ed., Handbook of Integrated Pest Management for Turf and Ornamentals, Boca Raton: Lewis Publishers, 1994; Rhay, T., "Maintenance of Infields and Other Bare Soil Areas," in A. R. Leslie, ed., Handbook of Integrated Pest Management for Turf and Ornamentals, Boca Raton, Lewis Publishers, 1994; Rhay, T., "IPM in Municipal Parks Maintenance-A Case Study," in A. R. Leslie, ed., Handbook of Integrated Pest Management for Turf and Ornamentals, Boca Raton, Lewis Publishers, 1994; Rhay, T., City of Eugene Public Works Maintenance Division, personal communication, October 7, 1997.

25. Diniz, E. V., 1980, Porous Pavement Phase 1—Design and Operational Criteria, Municipal Environmental Research Laboratory Office of Research and Development, U.S. Environmental Protection Agency, Cincinnati, Ohio, EPA-600/2-80-135, 1980; City of Olympia, Public Works Department, Water Resources Program, Impervious Surface Reduction Study—Final Report, May 1995; City of Olympia, Public Works Department, Water Resources Program, Impervious Surface Reduction Study—Henderson Field Demonstration Project Summary, June 1996; Wells, C., Study Coordinator, City of Olympia Public Works Department, personal communication, September 30, 1998.

26. U.S. Environmental Protection Agency. President Clinton's Clean Water Initiative: Analysis of Benefits and Costs, 800-R-94-002, Office of Water, Washington D.C., March 1994, p. 19.

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