Stormwater Best Management Practices in an Ultra-Urban Setting: Selection and Monitoring
3.9 Other Nonstructural BMPs
Nonstructural BMPs focus on prevention and removal of stormwater volumes and constituent loads at their source. While little data is available on the effectiveness of nonstructural BMPs their implementation is based on good common sense (Roesner, 1995). When space is too limited for the use of structural BMPs, such as in ultra-urban areas, nonstructural BMPs may be among the most cost-effective options available for reducing water quality constituents in stormwater runoff. When used in conjunction with structural BMPs, they may improve BMP efficiency and help to reduce maintenance requirements by reducing the accumulation of trash and sediment.
Examples of nonstructural BMPs range from activities such as land use planning and infrastructure maintenance to more site-specific activities. Examples of site-specific nonstructural BMPs applicable to ultra-urban areas include, but are not limited to:
- Materials management practices that prevent either rainfall or stormwater from collecting and transporting water quality pollutants.
- Road and storm drain maintenance practices such as streetsweeping and catch basin cleaning.
- Controls on illegal dumping.
- Landscaping practices that reduce or eliminate the use of fertilizers and pesticides.
Many of these practices can be implemented at different levels of involvement ranging from individual action to municipal, state, or business initiatives (Figure 30). For individuals, this can mean changing the products they use, how they use them, or how they eventually dispose of them. Even changes in behavior such as joining a car pool can be considered effective nonstructural BMPs (CDM, 1993). Highway agencies or departments of public works can change many of their practices, including how they store materials like road salt and sand, complete road repairs, or maintain their vehicles. Commercial businesses and industrial facilities may also implement a variety of generally site-specific nonstructural BMPs voluntarily or as a result of ordinances or regulations. Road and highway bridge cleaning, deck drainage, and painting activities may also require special nonstructural measures to mitigate effects on the atmosphere and receiving waters.
A comprehensive implementation of nonstructural BMPs, including an education and participation component, is best achieved through the implementation of stormwater pollution prevention plans. This is particularly true for municipalities, government departments, and businesses whose diverse activities can affect both stormwater quantity and quality. A key element of these plans is an active education and participation program to inform the public, municipal employees, or businesses of particular programs and their various options.
These stormwater pollution prevention plans and nonstructural BMPs can play an important role in watershed planning for stormwater management. Highway agencies and departments of public works may consider participating as a stakeholder in these comprehensive programs, which can be very effective at preventing or reducing water quality constituents in stormwater runoff from ultra-urban areas.
Options for implementing nonstructural BMPs focus on identifying activities that have the potential to negatively impact stormwater. These activities may result in changes in the water quality of stormwater, primarily through the input of new materials such as toxic chemicals, nutrients, or salts. Using these materials on impervious surfaces facilitates their direct input into stormwater drainage systems. In many cases, stormwater quantity or hydrologic changes also contribute to the impacts on water quality and aquatic biota. Once a problem has been identified, there is a need to develop alternatives for both individuals and groups to minimize their effects on both stormwater quality and quantity.
Nonstructural BMPs that can be implemented by individuals include:
- The use of safer or alternative products for lawn care.
- The proper disposal of hazardous wastes.
- The proper maintenance and care of vehicles.
The use of fertilizers can be minimized by establishing grasses and other ground covers recommended for the local climate region by the local municipality or the local Cooperative Extension Service of the U.S. Department of Agriculture. Using grasses that have been found to grow best in an area and are the least susceptible to diseases generally reduces the need to use fertilizers and pesticides. Proper watering and mowing also reduce the need for fertilizers and pesticides by encouraging the growth of a thick lawn (CES, 1993). Homeowners who use lawn care companies to maintain their lawn can, in many cases, switch to lawn care programs that are less reliant on chemicals. The use of low-maintenance alternative ground covers or reducing the size of a lawn also reduces the need to use fertilizers and pesticides (Bormann et al., 1993).
Stream Team Program
The Stream Team program developed in Prince George 's County, Maryland (Prince George 's County, 1993) has four different projects that interested groups can agree to perform to benefit their adopted stream or stream watershed. These include stream cleanups to remove trash from the streambed and stream banks, storm drain stenciling to educate the public that storm drains lead to the local stream, tree planting to create or increase forested buffers along the adopted stream, and an education and action plan for individuals to learn about a wide variety of environmental issues and to make personal changes in their own daily activities.
Cars and car care practices also contribute to stormwater pollutants. These constituents come from the phosphates found in soaps used to wash cars, leaks and spills of oil and antifreeze, and toxins found in the paints, polishes, and cleaners used to care for cars. To reduce and prevent these potential sources, car owners should avoid the use of phosphate-based soaps for car cleaning (or use a commercial car wash), repair leaks from their cars, recycle used oil and antifreezes, keep their car properly tuned, and be careful in their use of car paint, polishes, and cleaners. To prevent the inadvertent entry into storm drains of materials such as used motor oil, antifreeze, and paints and pesticides, these products should be taken to a hazardous waste site for disposal. Small amounts of these compounds can have toxic effects on downstream aquatic biota or may contaminate drinking water supplies.
Municipalities can not only adopt the use of alternative products and practices in their own everyday activities, but can also assist individuals in their efforts by providing advice and information on nonstructural BMPs and by implementing hazardous waste collection and disposal sites or systems. A number of municipal activities, such as maintaining vehicle maintenance and storage yards, implementing roadside and park landscape practices, optimizing road sand and salt application, and properly storing and using hazardous materials, can reduce the impact of these practices on water quality (Figure 31). Nonstructural measures include methods that cover material storage piles and hauling equipment to prevent rainfall from washing constituents into stormwater, prevent or reduce stormwater runoff from vehicle maintenance and parking areas, or reduce the need and use of potential stormwater contaminants such as salt and pesticides (Figure 32).
The municipality may also use ordinances to require commercial and industrial businesses to develop and implement specific nonstructural BMPs, such as requiring a dike around garbage disposal bins to contain spills and runoff from the immediate area. Many municipalities have also developed programs to identify and disconnect illicit connections to their storm drain system. In a Wisconsin community, a water quality protection manual has been developed to inform businesses of the importance of using BMPs and the options available for their participation (WC and UWIN, 1996). High-visibility, low-cost programs such as the Adopt-a-Road and Adopt-a-Stream programs are also effective in raising environmental awareness and helping to reduce trash problems in ultra-urban areas. These programs generally require minimal organization and advertising, and the provision of collection bags and pick-up sites for the clean-up program.
Ordinances can also be extended to require specific types of businesses or industries to develop and implement a pollution prevention plan. The key elements of the plan, in some cases already required by state or federal regulation, include a process with five main phases (USEPA, 1992).
- Planning and organization.
- Site assessment.
- BMP selection and plan design.
- Implementation of plan.
- Evaluation and monitoring.
The first phase requires the planning and organization of staff and review of existing environmental facility plans. This includes identifying the persons who will develop, implement, maintain, and update the plan — usually those most familiar with the facility and how it operates. The site assessment or second phase of the plan requires the development of a site map showing features relevant to stormwater management, including drainage paths and discharge points, surface water bodies, stormwater drainage system and outfalls, an inventory and the location of significant materials exposed to stormwater or rainfall, the identification and location of past spills and leaks, and the identification and location of non-stormwater-related discharges to storm drains.
BMP selection and plan design is the third phase of a pollution prevention plan. This phase focuses on good housekeeping, preventive maintenance, visual inspections, spill prevention and response, sediment and erosion control, stormwater management, and employee training. The fourth and fifth phases of the plan are implementation and evaluation and monitoring. Implementation requires the development of a schedule for activities, the delegation of responsibilities, and the organization of employee training. Evaluation and monitoring requires that an annual site compliance evaluation take place and that procedures for record keeping, internal reporting, plan revisions, and updates be formalized.
Commercial and Industrial
Best management practices can also be incorporated into new construction. A car dealership in Wisconsin has used a mix of structural and nonstructural stormwater management practices to help protect a nearby trout stream. The car lot design demonstrates the use of a number of practices, including clean water diversion, stormwater infiltration beds for roofs and paved areas, grassy swales, and zinc-free roofing (Struss, 1993).
Commercial areas such as retail and service-related businesses can ensure that their properties are properly maintained, that garbage bins are used and not overflowing, that parking lots are cleaned with sweeping equipment, and that road surfaces are maintained. The use of low-maintenance ground covers to meet landscaping needs can reduce the need for watering and for the use of pesticides. Specific businesses, such as service stations, can also be encouraged to improve their stormwater management by voluntarily developing and implementing pollution prevention plans. Industrial activities are likely to require a pollution prevention plan for their particular site as a result of state or federal regulation. This plan should deal with the issues outlined earlier, including activities such as the handling, storage, use and disposal of hazardous materials; maintenance; and recycling programs. Industries should investigate all non-stormwater discharges to storm drains and identify and remove illicit storm drain connections. In particular, vehicle washing, fueling, and maintenance areas often need measures to prevent the contamination of stormwater.
Highway and Road
The use of road salt can be optimized in a number of ways:
- Salt storage piles need to be completely covered.
- Storage and handling operations should be done on impervious surfaces.
- Stormwater runoff from areas were salt is stored should be contained in a suitable area.
- Trucks can be equipped with ground-speed sensors that can accurately control the rate of spreading.
- Training programs for drivers and handlers should be implemented to improve the efficiency of application and to reduce losses.
- Snow plow operators need to avoid piling snow on or near frozen ponds, lakes, or wetlands.
Road Departments and Municipalities
- Can identify ecosystems, particularly wetlands, that are sensitive to salt.
- The use of alternatives to salt such as calcium chloride and calcium magnesium acetate may be less environmentally harmful to sensitive ecosystems. These alternatives are more expensive than regular salt, but are also less corrosive to bridges and overpasses.
- In some instances, sanding may be used in place of salt to improve traction (Lawson, 1993). However, in other instances, sanding may not be appropriate where sedimentation has adverse environmental impacts.
Highway and road maintenance and repair programs need to establish and use procedures that reduce or prevent stormwater pollution. Nonstructural BMPs recommended include provisions for landscaping and vegetative practices, pesticide and fertilizer management, litter and debris controls, illicit discharge controls, bridge cleaning and deck drainage, bridge painting, and chemical storage. These BMP options range from innovative programs to conventional good common sense. For example, in a town in Vermont the use of infrared sensors mounted on salt trucks to measure pavement temperatures (as the basis for salt application rates) has reduced the use of salt by 15 percent (Lawson, 1993). This "smart salting" program reduces pollution and also saves money. A more conventional approach to salt management and use is illustrated below.
In addition to general nonstructural BMPs, highway and road departments can prevent the contamination of water bodies by restricting equipment from entry into water and by requiring equipment refueling and stockpile setbacks from water bodies. Examples of many nonstructural BMPs and how they can be implemented, along with their associated cost, can be found in the Evaluation and Management of Highway Runoff Water Quality (Young et al., 1996).
More detailed information on nonstructural BMPs can be obtained from municipal, state, and federal agencies and environmental organizations that deal with stormwater management issues (CDM,1993; Greenfield and LeCouteur, 1994; Mills and Eckert, 1996; USEPA, 1993).
The effectiveness of nonstructural BMPs relies heavily on educational and participation programs that target schools, public service organizations, municipal employees, businesses, and the general public. It also relies on the leadership of government departments -- particularly highway and road departments, which are an important and very visible component of every community. The leadership shown by both adopting and facilitating educational programs for nonstructural BMPs improves the community-wide acceptance of such practices.
Educational programs work best when they increase the level of environmental awareness in the target audience and convey a clear link between people 's everyday activities and stormwater quality impacts. The stenciling of storm drain systems with educational language or graphic icons, for example, helps discourage the dumping of hazardous materials such as used motor oil and paint into storm drains. Probably just as importantly, it raises the environmental awareness and knowledge level of program participants with respect to stormwater management issues. Education programs can also increase the public scrutiny of industrial and municipal practices, with a resulting increase in the reporting of incidents such as spills or illegal discharges to storm drains.
Costs of nonstructural BMPs are primarily incurred in proportion to the level of effort and the methods used in an education and public relations program. These efforts can range from the use of display booths, posters, decals, school packets, and public service announcements to developing awareness using local news programs and other media. Efforts can also involve the development of alliances with neighborhood groups, civic organizations, and business associations (Watson, 1994).
Capital costs may be incurred for the purchase of streetsweeping equipment and spill cleanup and prevention equipment, material storage, or implementation of pollution prevention plans. The installation of roadside barriers to prevent illegal dumping in stream valleys and the removal of illicit connections to storm drains also require capital expenditures and in many cases the cooperation of individuals and government agencies.
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Cooperative Extension Service (CES). 1993. General Guidelines for Lawn Maintenance in Maryland. Agronomy Mimeo 90. Cooperative Extension Service, U.S. Department of Agriculture, University of Maryland at College Park, College Park, MD.
Camp Dresser & McKee (CDM), Larry Walker Associates, Uribe and Associates, and Resources Planning Associates. 1993. California Stormwater Best Management Practice Municipal Handbook, BMP: Vehicle Use Reduction.
Greenfield, J., and B. LeCouteur. 1994. Chesapeake Bay Community Action Guide, A Step-by-Step Guide to Improving the Environment in Your Neighborhood. Metropolitan Washington Council of Governments, Department of Environmental Programs, Washington, DC.
Lawson, M. 1993. Maintenance Engineer, Vermont Agency of Transportation, Montpelier, VT. Cited in Nonpoint Source News Notes, Issue 39.
Mills, A., and D. Eckert. 1996. Conscious Living in Suburbia. Audubon Naturalist 22(3).
Prince George 's County. 1993. Stream Teams, Citizen Volunteer Monitoring Program. Department of Environmental Resources, Prince George 's County, Largo, MD.
Roesner, L. 1995. Common-Sense City, Country Controls. Water Environment and Technology, September, pp. 60-64.
Struss, R. 1993. Cars+Trout=Satisfied Customers All Around. In SWWM News and Notes, 4(1):12
United States Environmental Protection Agency. 1992. Storm Water Management for Industrial Activities, Developing Pollution Prevention Plans and Best Management Practices. EPA 833-R-92-002. U.S. Environmental Protection Agency (USEPA), Office of Water, Washington, DC.
USEPA 1993. Guidance Specifying Management Measures For Sources Of Nonpoint Pollution in Coastal Waters. EPA 840-B-92-002. U.S. Environmental Protection Agency, Office of Water, Washington, DC.
Watson, J. 1994. Non-Point Source Pollution Communications and Outreach Plan for the Waukesha County Department of Environmental Resources. Knupp & Watson, Inc., Madison, WI.
Waukesha County and University of Wisconsin-Extension (WC and UWIN). 1996. Quality Protection Manual for Waukesha County Businesses. Waukesha County, Department of Parks and Land Use, Land Conservation Division, Waukesha, WI.
Young, G.K., S. Stein, P. Cole, T. Kammer, F. Graziano, and F. Bank. 1996. Evaluation and Management of Highway Runoff Water Quality. FHWA-PD-96-032. Federal Highway Administration, Office of Environment and Planning.