Introduction

Municipal stormwater management is an evolving field where traditional practices and new ideas are integrated to yield the best management approach. This is the most difficult module to write as it requires significant inputs from municipal engineers and planners who know the daily operations in a municipal setting. We are still consulting municipal staff in this respect and hope an update will be forthcoming in the very near future. With our limited experience and knowledge in municipal practices, we attempt in this module to bring out new ideas in municipal stormwater management and wish the debate will encourage constructive approach in stormwater management in the municipal setting. The module overviews municipal stormwater management and related issues.

Municipal Stormwater Management

Stormwater management is one of the issues in municipal land use planning and infrastructure operation and maintenance. The traditional land use planning involves a hierarchy of planning processes which results in the development of official plans, secondary plans, and subdivision plans. In order to protect the water environment as well as serve development needs, municipalities have to understand the effect of urbanization on the water environment at every step of the planning process. To make a broad level decision on land use designation at the official plan, municipalities need to know water management constraints and targets at a watershed level. Thus, a watershed management plan should be conducted for the purpose of preserving and rehabilitating key water ecosystem components while allowing sustainable development. Subwatersheds which are important in the watershed management context should be further studied to determine subwatershed constraints and targets, and the locations and control criteria of regional control facilities. Such information will allow municipalities to better plan their infrastructure and services to support new development at the secondary planning level. Finally, stormwater management plans have to be developed to support subdivision and site plans.

Municipal infrastructure operation and maintenance activities provide excellent opportunities to address stormwater management issues. As the final owner of all stormwater management facilities, municipalities have to be careful in guiding development engineers in the planning and design phase of stormwater management practices. Facility related issues such as suitability, cost-effectiveness, operation and maintenance requirements, and liability are important considerations to municipalities.

Non-Structural Measures

Municipal stormwater-related practices may include:

• catch basin and street cleaning;
• control of road de-icers;
• control of fertilizers and pesticides;
• enforcement of anti-litter and discharge by-law;
• public education;
• sewer rehabilitation;
• water conservation;
• erosion and sediment control;
• used oil recycling;
• household hazardous waste collection;
• safe alternative products; business education and awareness;
• material storage controls;
• vehicle use reduction;
• yellow fish road program;
• pool drainage;
• pills control;
• leaf clearing and removal;
• modifying engineering standards; and
• cross connection control program.

Each of the above measures are discussed in the following sections (TSH, 2000a and 2000b).

Catch Basin Cleaning

Catch basins and stormwater inlets are flushed or cleaned on a regular basis to remove accumulated sediments. This measure can reduce high pollutant concentrations during first flush of storms, prevent clogging of the downstream conveyance system, and restore the catch basin's sediment-trapping capacity (Butler and Karunaratne, 1995). Municipal staff should inspect public and private facilities on an annual basis to ensure compliance with the following:

• Cleaning should occur before the sump is 40% full.
• Cleaning catch basins and inlets in areas with the highest pollutant loading and in areas near sensitive water bodies.
• Operation logs of which catch basins were cleaned and how much waste was removed should be kept to tract program.
• Goss traps should be installed at catch basins to restrict oil and floatables from entering the sewers.
• The metal content of decant and solid cleaned from a catch basin should be periodically tested to determine if the decant violates limits for disposal to wastewater treatment plant or if the solids would be classified as a hazardous waste.

Two-person teams are required to clean catch basins with vacuum trucks. Crews must be trained in proper maintenance, including record keeping, disposal and safety precautions. Arrangements must be made for the proper disposal of the collected wastes. An aggressive catch basin cleaning program could require a significant capital, operation and maintenance budget because of the typically large number of catch basins in any given area and the high cost of labour and equipment required to do the work. Smaller municipalities may elect to contract work out as an annual contract.

Street Cleaning

Some reduction in the buildup of pollutants on street surfaces can be accomplished by conducting street cleaning on a regular basis. The primary and historical role of street cleaning is for sediment and litter control. Cleaning frequency should be based upon inter-event times. Some studies indicate that 50% removal of street dirt may be achieved by a sweep frequency of 1 or 2 times during the average interval between storms (Pitt 1998). Accurate operation logs should be kept of curb kilometres swept and amount of waste collected to tract program. Climate, parked cars, street and curb conditions, traffic congestion, and construction projects may limit the effectiveness of this measure. In order to apply this measure effectively, a municipality should prepare to

• Hire sweeper operators and maintenance staff, supervisory and administrative personnel;
• Enforce parking restrictions by traffic control;
• Design optimal cleaning routes;
• Dispose collected wastes properly; and
• Buy or lease mechanical broom sweepers for large debris and vacuum sweepers for fine particles.

Normal street cleaning operations for aesthetics and traffic safety purposes are not very satisfactory from a stormwater quality perspective. Unless the street cleaning operations can remove the fine particles, they will always be limited in their pollutant removal effectiveness. The ability of street cleaning to improve runoff quality is dependent on many issues, including the local rain patterns and other sources of runoff pollutants.

Control of Road De-Icers

The goal of a winter operations program is to provide safe road conditions without losing sight of the cost implications and potential negative impacts to the environment due to misuse of chemicals, including road salt and other de-icing compounds (Environment Canada, 2000). Manual spreaders can be monitored and adjusted by the operator based upon truck speed. Pre-wetting of solid salt has been proven to keep more material on the road surface as opposed to being blown away by passing vehicles. Pre-wetting salt quickens its melting action and enhances its melting effect at low temperatures.

Past practices for winter road maintenance on local residential streets included waiting until 25 mm or more of snow accumulated before beginning to plow and treating with chemicals which frequently lead to the development of "pack". Removal of this compacted layer tightly bonded to the pavement is called de-icing. This technique usually requires a large quantity of chemical to work through the pack to reach the snow/pavement interface and break it up. Arterial and collector streets receive application of salt at an earlier stage of snowfall, often at the onset of snow, in order to maintain traffic safety.
Application of liquid chemicals on dry pavement prolongs the period of time during a snowfall or temperature drop until ice starts to form.

Control of Fertilizers And Pesticides

The reduced use of fertilizers and pesticides can be promoted through the use of Plant Health Care Programs. These can be designed for municipal, commercial and residential uses. By consistently employing a particular organic set of horticultural practices, healthy turf growth can be encouraged while having the smallest possible environmental impact. Shrubs, trees, flowers and walkways can be used as attractive replacements for the traditional lawn.

An integrated Pest Management Program can be used to promote biological controls using "beneficial" insects as alternatives to pesticides (e.g., ladybird beetles, preying mantis) as well as "companion plantings" to discourage insects.

A chemical reduction program need not advocate a complete ban on pesticide use, but can recognize that there may be occasions when spraying may be necessary.

Naturescaping promotes natural lawn care techniques and encourages lawn replacement with alternatives, including drought-tolerant plants. Many alternatives are available for pest and weed control, including the use of beneficial insects, companion plantings and alternative spray compounds, such as soap and other more environmentally friendly substances. Public education will be needed to produce support for chemical reduction in parks and public use areas.

Public education programs can also promote reduced horticultural chemical use around residences. This may include media publicity, educational material, e.g., brochures, lawn signs, park display areas with interpretive signage, and community promotional events. Some neighbourhood groups or individuals may be strongly opposed to the program because of their aesthetic preferences for traditional lawns, and because of perceived health and safety risks.

Enforcement Of Anti-Litter And Discharge By-Law

Municipalities may pass bylaws for the maintenance and management of its sewers, sewer system, sewage works, treatment works and watercourses, and regulate the manner, extent and nature of the reception and disposal of sewage and land drainage. Litter, usually consisting of packaging material, is discarded by individuals over the urban landscape. Pet faeces are deposited primarily by dogs and left uncollected by owners. Both types of litter end up in storm drainage and cause problems.

Control programs involve changing individual's behaviour by preventing the littering action. Littering bylaws with enforcement are the "backbone" of the prevention programs.

Introduction of Stoop and Scoop and Anti-Litter bylaws should be accompanied by both a public education program and enforcement arrangements. Public education can include media promotion, Stoop and Scoop signing, distribution of "doggie" collection bags in parks, and through business sponsors such as veterinarians and pet stores. Bylaw officers are required to provide enforcement where necessary (CDM, 1993). Summer students or part time staff may be used to carry out some public education programs for the Anti-Litter and Stoop and Scoop By-laws. The cost of promotional materials will vary according to the type used and method of distribution.

Public Education

The public should be informed about pollution prevention, stormwater management issues and solutions, regulations and related financing (LWA, 1999). By involving the public in remedial action, it can save cost through volunteerism and increase political support.

A public education process involves the following steps:

1. Prepare the program;
2. Identify the problem and the solution;
3. Seek information and resources;
4. Identify and understand the target group;
5. Identify partners;
6. Design the plan;
7. Identify the product or desired result;
8. Consider costs and time limitations;
9. Consider roles and responsibilities of coordinator agency and partners;
10. Design promotion material and means of distribution;
11. Implement the plan;
12. Pre-test the plan and make necessary changes;
13. Implement the plan and actions;
14. Monitor the effectiveness of the public education; and
15. Monitor the effectiveness of the plan as a solution to the initial problem

Key public education messages can focus on the pollutants and impacts of stormwater and encourage individuals to protect the health of local creeks, streams, rivers, lakes, bays and oceans (WERF, 1998).

Sewer Rehabilitation

Rehabilitation of sewer infrastructure improves conveyance and retains structural integrity. Inflow and infiltration (I/I) to sanitary sewers should be minimized to prevent overloading the sewage treatment plant and flooding basement (EPA, 1991) . Inflow refers to water flowing into the sanitary sewer during wet weather through direct connections to downspouts or surface connections through manhole covers. Infiltration flows generally occur after rain events are over and are basically groundwater. Rainfall induced infiltration can occur where surface drainage gains access to foundation drains connected to the sewer.

The first step in an I/I evaluation program is to identify inflow and infiltration problems through examination of flow records at sewage treatment plants and in major sewer interceptors. Individual sewers should then be examined by visual inspection either manually or with television cameras to locate cracked and broken pipes and private connections. Basement flooding records can locate areas where I/I problems may exist (however, the source of the inflows may be far removed from the flooding areas).

Sewer rehabilitation methods include complete sewer replacement to replacing or repairing catch basins, manhole repair, and replacement of manhole covers (ASCE, 1983). Many technologies are available for relining sewers and repairing and replacing sewers without digging up the street (trenchless technologies). Storm sewer rehabilitation is carried out often in conjunction with road repair and replacement. The need for storm sewer rehabilitation is often identified through surface flooding problems or structural deficiencies discovered by visual examination of the sewer. For sanitary sewers, the methods would be applied based on the existence of excessive wet weather flows at the sewage treatment plant, structural integrity problems or basement flooding. Municipalities have a duty to maintain infrastructure in good operating condition. Due diligence through active inspection programs and sewer rehabilitation will avoid problems caused by collapsed sewers such as flooding and sewer back-ups.

Water Conservation

Water conservation and water efficiency programs are used to reduce the volume of household and industrial water entering combined and sanitary sewers and wastewater treatment plants. This lowers the risk of combined sewer overflows during rainy weather and improves the operating efficiency and long-term performance of wastewater treatment facilities and septic tanks. Water conservation programs also reduce the demand on groundwater resources especially in dryer seasons and provide a cost-saving benefit for industries and other large volume users (OWWA, 1999).

Public outreach and education is the most significant component of a water conservation program. This can range from providing information with utility bills to a major social marketing program to reach a specific reduction target. Other approaches include:

1. Integrate efforts with naturalization and pesticide reduction programs for public lands;
2. Integrate water efficiency planning into municipal water supply and wastewater treatment strategies;
3. Use social marketing or educational programs for householders, businesses and industries to change water use habits and attitudes;
4. Produce and distribute water conservation educational brochures and printed information;
5. Develop media contacts, press releases and promotional events to promote water conservation;
6. Integrate public outreach programs or publication development with agencies or organizations with a compatible agenda.
7. Develop incentive programs to facilitate the installation of residential low flush toilets and water saving devices;
8. Use metering and water pricing strategies to provide a cost saving incentive for the end user;
9. Reduce operational water use on public parks and municipal lands;
10. Promote alternative landscaping or gardening practices which reduce the need for summer peak watering;
11. Develop industrial and commercial information materials, workshops and water audit kits to promote water efficiency in the workplace;
12. Develop school programs, provide materials such as shower timers and small water saving devices, and incorporate a monitoring component as assigned homework.
13. Reduce water leaks where possible.
14. Consider on-site water reuse as a means of conserving water.

Erosion And Sediment Control At Construction Sites

Erosion and sediment control is a responsible act that should be implemented on every construction site, before work begins and during construction. Planning of effective erosion and sediment control should follow these seven basic principles (Goldman et al. 1986): 1) Plan the development to fit the site; 2) Minimize the extent of the disturbed area and the duration of exposure; 3) Stabilize and protect disturbed areas as soon as possible; 4) Keep runoff velocities low; 5) Protect disturbed areas from runoff; 6) Retain sediment within the corridor or site area.; 7) Implement a thorough maintenance and follow-up program.

Erosion and sediment control practices can be classified into (Li, 1997): 1) Temporary Cover Practices (e.g. seeding, mulching); 2) Permanent Cover Practices (e.g. sodding, vegetative buffer strips); 3) Sediment Control Practices (e.g. silt fencing, straw bales, sediment basins, sediment traps, sewer inlet traps, temporary runoff controls, rock check dam, and interception berm/swale).

Used Oil Recycling

Used oil recycling is a responsible alternative to improper disposal practices, such as dumping in the sanitary sewer or storm drain system, applying oil to roads for dust control, placing used oil and filters in the trash for landfill disposal or simply pouring used oil on the ground (CDM, 1993).

The following approaches may be effective for used oil recycling:

1. Integrate efforts with a municipal solid waste program that likely has already been established.
2. Set up a municipal collection centre funded by the municipality.
3. Contract out the collection and hauling of used oil to a private hauler/recycler.
4. Utilize the automobile service industry for collection of used oil.
5. Work with automotive parts supply stores to reduce incidents of automotive fluids left by customers on paved areas.
6. Create procedures for collection such as collection locations and schedule, acceptable containers and maximum amounts accepted.
7. Promote public participation through the use of posters, handouts, brochures and announcements in print and broadcast media; provide a list of the commercial recyclers.
8. Develop incentive programs for commercial locations and used oil recyclers.

Arrangements must be made for collection and delivering waste oil to a recycling facility. A staff person is needed to coordinate these arrangements and review alternative arrangements such as contracting out collection and haulage.

Household Hazardous Waste Collection

This measure focuses on the collection of deleterious chemicals that sometimes are disposed of in a manner that threatens stormwater or sanitary sewage quality. Household hazardous wastes (HHW) are defined as waste materials that typically are found in homes or similar sources and exhibit characteristics such as corrosivity, ignitability, reactivity and /or toxicity, or are listed as hazardous materials.

Household hazardous waste products include drain openers, oven cleaners, wood and metal cleaners and polishes, automotive oil and fuel additives, grease and rust solvents, carburetor and fuel injection cleaners, starter fluid, batteries, paint thinners, paint strippers and removers, adhesives, herbicides, pesticides, fungicides and wood preservatives.
Household hazardous waste collection is a preventative, rather than curative measure and may reduce the need for more elaborate treatment controls. Pollutants from household waste also end up in combined sewer discharge, biosolids from the sewage treatment plant in sewage effluent, and for volatile organics, as an air pollutant. The benefits to storm water quality from HHW collection is unknown at present but best engineering judgement indicates a potential of up to 15% reduction in loadings (SQTC, 1993).

The following considerations may be applicable for this measure.

1. Integrate efforts with a municipal solid waste program that may have already been established.
2. Optimize collection method(s) (for example, permanent, periodic, mobile and curbside) and frequency (for example, monthly and quarterly) based upon waste type, community characteristics, existing programs and budget.
3. Educate the public about hazardous materials in the home and the consequences of improper use or disposal.
4. Identify and promote the use of non-hazardous alternatives.
5. Identification of proper storage and disposal methods.
6. Promote participation in local HHW collection programs.
7. Distribute posters, handouts and educational material aimed at local schools.
8. Use public service announcements on local television networks, radio announcements, and newspapers.
9. Add utility bill inserts.
10. Make presentations to community organizations and develop a "speaker bureau" of local environmental professionals and recycling experts.

Safer Alternative Products

The use of less harmful and environmentally damaging products should be promoted. Alternatives exist for most product classes, including fertilizers, pesticides, cleaning solutions and most automotive and paint products. Promoting the use of less harmful products can reduce the amount of toxic and deleterious substances that enter stormwater and ultimately reach receiving waters (MOE, 1993; CCPP, 1998).

This measure has three key audiences: municipal employees, the general public and small businesses. Existing regulations already require municipalities to reduce the use of hazardous materials. Municipal employees who handle potentially harmful materials should be trained in the use of safer alternatives. Purchasing departments should be encouraged to procure less hazardous materials.

Safer alternatives for use by the general public are presented through education. Awareness is the key to successful implementation of this measure. It promotes a willingness to try alternatives and modify old behaviours.

The following are examples of topics to be covered under a public education program.

1. Automotive products - Less toxic alternatives are not available for many automotive products, especially engine fluids. But there are alternatives to car polishes, degreasers and windshield washer solution. Re-refined, recycled oil is also available.
2. Cleaners - vegetable based or citrus-based soaps are available to replace petroleum-based soaps/detergents.
3. Paint products - Water based paints, wood preservatives, stains and finishes are available.
4. Pesticides - Specific alternative products or methods exist to control most insects, fungi and weeds.
5. Fertilizers - compost and soil amendments are natural alternatives.

Materials Storage Controls

Material storage controls can prevent or reduce the discharge of pollutants to stormwater from material delivery and storage areas. This can be done by reducing the storage of hazardous materials on site, storing materials in designated areas, installing secondary containment, conducting regular inspections and training employees and subcontractors.

Material storage areas should be designed and maintained by:

1. Storing materials inside or under cover on paved surfaces;
2. Using secondary containment, where needed;
3. Minimizing storage and handling of hazardous materials and Inspecting storage areas regularly;
4. Keeping an ample supply of absorbent spill clean-up materials near the storage area.

This is a preventative practice where the benefits include reduced liability, due diligence, and improved public image for commercial operations.

Employees must be educated in the proper handling and storage of materials on site. Storage sheds and designated areas must meet building and fire code requirements. Accurate and up-to-date inventories should be kept of all stored materials.

Vehicle Use Reduction

Studies show that reducing vehicle deposits on roadways is likely to have a significant impact on local water quality, with potential improvement in aquatic habitat. Highway drainage has been shown to be toxic (Marsalek et al, 1999). There should be a reduction in the amount of pollutants entering major lakes and rivers, and some reduced costs of pollutant removal at water intake plants. Highway expansion needs and road maintenance costs may also be reduced.

Efforts should be integrated with:

1. government agencies, business and municipal programs to reduce vehicle use to improve air quality and public health;
2. transit system redesign, expansion, and transit use promotions;
3. residential street redesign including the addition of bicycle lanes and traffic calming initiatives;
4. subdivision planning through community trail design, neighbourhood focused services;
5. local bicycle and road safety programs;
6. ride-share and trip reduction programs at government offices, major employers and universities;
7. car-pooling between urban centres by the provision of no cost commuter parking, commuter lanes and toll reduction incentives;
8. idling by-laws to reduce emissions; and
9. encouragement of alternative form of transportation, such as walking, bicycles and transit.

Yellow Fish Road Program

Stencilling of storm drain system (inlets, catch basins, channels and creeks) with warnings/advisories and graphic icons discourages the illegal dumping of unwanted materials. Advisories are distributed to homes in stenciled areas. An effectively implemented stencilling program encourages change in personal behaviour and helps minimize non-point source pollutants from entering the storm drain system. Catch basin maintenance is simplified through the reduction of disposed materials into storm drain inlets.

A volunteer workforce is created to stencil storm drain inlets, preferably with school children or scouting and guiding groups to reflect the initial principle of the program. Volunteer activity must be limited to low traffic areas with municipal staff taking responsibility for high traffic and congested areas. Education of groups, coordination and provision of standard stenciling kits is necessary. The program should also aid in the cataloging of the storm drain system.

The primary staff demand is for program setup to provide marketing and training. A minimum of two persons is required for stenciling in high-traffic areas and commercial and industrial zones with appropriate safety measures in use (for example, reflective vests, flag person and signage). The storage and maintenance of stenciling kits requires planning.

Storm drain stencilling kits include stencil, paint, paint brush, plastic gloves, catch basin map, clipboard, instructions, liability release form, identification form, rags, whisk broom or brush, paper towels, trash bags, safety vest and a 5 gallon bucket to hold materials.

Pool Drainage

Outdoor swimming pools require regular maintenance, involving chemical treatment, backwashing (rinsing the filter with clean water), and winterising. The drawdown of pools prior to winter may release a large volume of water to the surface water or to combined sewers. Pools and spa water containing chlorine can be toxic to aquatic life. Pool backwash water containing sediment can cause sediment pollution of surface waters (WERF, 1998).

Advice should be given to landowners by municipalities, conservation authorities and resident associations on environmentally acceptable ways to discharge pool backwash water and drawdown water for winterizing. Potentially toxic discharges should be avoided while groundwater infiltration should be enhanced. In combined sewer areas, flow reduction will result in reduced operational costs for conveyance and treatment.

Chemical additives for pools include chlorine or bromine, to maintain pool quality, and products such as pH-up or muratic acid, which are occasionally used to maintain acid balance. Weekly backwashing is necessary to remove particles from the pool filter. Backwashing can draw down the pool water level by about 25 mm, and the backwashed water, containing sediments collected on the filter, is usually discharged to the lawn or driveway. In the fall, owners must blow out the pool lines (i.e. circulation, pump and filter) to avoid freezing and cracking over the winter. This winterizing activity usually results in the drawdown of in-ground pool water level by about one quarter of the pool volume, while above ground pools and spas are completely emptied.

Public education programs should stress the following:

1. In order to have the least environmental impact, pools should be emptied at least three days after the last intense chemical application. The chlorine residual should be virtually absent.
2. Backwash water is contaminated by filtered sediments and pool operators should discharge this water either to the sanitary sewer, or across the lawn to the storm sewer. By allowing pool water to flow across a lawn, some water will be lost through infiltration, some sediment will be filtered, and most remaining pool chemicals will volatilize to the air.
3. If backwash water is discharged to the sanitary sewer, residents should take care to not also discharge winter drawdown water to the sanitary sewer because of the potential impacts of increased flow volume.
4. In combined sewer areas, where no storm sewer exists, residents should be aware of the impacts of additional flow on the conveyance and treatment system. In these areas, infiltration measures should be encouraged to reduce the volume of water draining to the sewer system.
5. Residents should be advised not to discharge the pool water onto neighbouring properties.
6. Residents should be discouraged from discharging pool water into ravines to avoid erosion and slope failure.

Spill Control

Prevention or reduction of discharge of pollutants to stormwater from above ground storage tanks can be done by installing safeguards against accidental releases, installing secondary containment, conducting regular inspections and training employees in standard operating procedures and spill cleanup techniques. Vehicles and heavy equipment will leak and spill fluids. The key is to reduce the frequency and severity of leaks and spills and when they do occur, prevent or reduce the environmental effects.

Transportation related spills are difficult to prevent. A rapid spill response is necessary in these cases to control spills.

Efforts should be integrated with existing storage tank programs, through the local fire and health departments, and with the local emergency response plan coordinated by the municipality.

The following considerations may be effective in reducing spills associated with vehicle and machinery use:

1. Perform fluid removal and changes inside or under cover on paved surfaces;
2. Keep equipment clean and do not allow excessive build-up of oil and grease;
3. Washwater should be properly filtered and disposed;
4. Recycle greases, used oil and filters, antifreeze, cleaning solutions, automotive batteries, hydraulic and transmission fluid;
5. Use dry cleanup methods;
6. Salt/pickled sand storage areas should be covered;
7. Drainage from stored materials should be treated to remove sediment.

Leaf Clearing And Removal

Some reduction in the discharge of nutrients and pollutants to stormwater from street surfaces can be accomplished by conducting leaf cleaning and removal during the fall season. The primary benefit of this activity is the removal of a high nutrient load from the storm sewer and ultimately the creek system, which enhances overall water quality.

The following approaches may be effective to implement and maintain a municipal leaf pick-up program:

1. Prioritize pick-up to use the most technically advanced sweepers or truck mounted vacuums designed especially for this activity, at the greatest possible frequency in areas with the greatest numbers of trees. Provisions must be made for dumping, as the on board storage fills quickly with the bulky material. Areas with heavy leaf deposits may be most easily cleaned with loaders and dump trucks or a tuck mounted vacuum system that discharges into the back of the truck.
2. Residents should be informed of leaf collection arrangements, such as location of leaf collection centres; use of 2-ply Kraft paper yard bags instead of plastic; curbside collection dates, restrictions and proper methods of accumulation. Residents should also be encouraged to dispose of leaf and yard waste in their own composters or by mowing and leaving on the lawn.
3. Keep accurate operation logs of tonnages collected to track program.

The following limitations may apply to this measure:

1. Parked cars are the primary obstacles to effective program if leaves are deposited at curb side.
2. The effectiveness may also be limited by traffic congestion, construction projects, and climatic conditions.
3. There is some potential for danger of children playing and hiding in curbside leaf piles.

Modifying Engineering Standards

Changes to engineering standards to promote the use of surface storage and drainage (through grassed areas) should be encouraged. For instance, the following changes can be recommended to the engineering communities:

1. Grading standards to promote surface ponding and / or increasing the detention time of surface water on grassed areas (MOE, 2000).
2. Reduction of the minimum and maximum surface slopes.
3. Provision of retention areas.
4. Road design standards to promote roadside swales.
5. Promotion of infiltration such as rock or stone filled basis or trenches to storm water for infiltration.

This measure requires the revision to engineering standards and site plan standards (and approval process) and requires public education for the acceptance of periodic surface ponding (and conveyance). Current design standards should be reviewed to ensure that they do not impede or prevent application of the source and conveyance measures. The existing infrastructure that is in rural cross sections utilizing roadside ditches should be maintained and upgraded to ensure that the benefits of this practice are maintained.

Cross Connection Control Program

A significant source of stormwater pollution can be removed by preventing unwarranted physical connections to the storm drain system from sanitary sewers and floor drains through regulation, regular inspection, testing and education. An active program will reduce liability (shows due diligence) for pollution from storm sewers (EPA, 1993).

The following steps are components of this measure:

1. Ensure that existing provincial municipal building and plumbing codes prohibit physical connection of non-stormwater discharges to the storm drain system.
2. Require visual inspection of new developments or redevelopments during development phase.
3. Develop documentation and record keeping protocols to track inspections and catalogue the storm drain system.
4. Use techniques such as zinc chloride smoke testing, fluorometric dye testing and television camera inspection to verify physical connections.

Building and plumbing inspectors must verify and document inappropriate discharges into the storm drain system. Additional follow-up time is required to verify that appropriate corrective measures have been carried out.

A community awareness program (using various media), can target appropriate audiences (homeowners, businesses and contractors) to warn against improper connections to the storm drain system and encourage public reporting of illegal connections through a community hotline telephone number.

Equipment needed for inspection programs may include:

• Personal protective equipment (hard hats, boots, plastic gloves, coveralls);
• Sampling containers and storm water test kits;
• Self-contained breathing apparatus;
• Oxygen/combustible and hydrogen sulphide gas meters;
• CCTV pipeline television camera;
• Smoke and dye testing equipment.

Community and local fire departments should be notified before testing with zinc chloride smoke testing and fluorometric dye testing in targeted areas.

Municipal Stormwater Pollution Prevention

Types of action a municipality can take to promote non-structural stormwater management measures include direct action, involvement with others, push for action, By-Law adoption and modifications, official plan policies, subdivision design policies and drainage standards. Each action is described in the following section.

Direct Action

A description of the actions that can be taken are discussed in the following items.

1. Develop a Pollution Prevention and Control Plan (PPCP) - if the problem is complex and related to multiple sources such as combined sewer overflows, stormwater and point sources from municipal sewage treatment or industry. Simpler PPCP studies can be developed for stormwater retrofit situations, to narrow the scope of study to stormwater only.
2. Develop an Environmental Management System (EMS) - if pollution prevention on a broad scale is desired, and additional benefits are of interest, such as increased environmental performance, improved accountability, and reduced liability for environmental damage. The scope of the EMS can be municipality wide or apply to environmental and works departments or individual facilities.
3. Develop a Pollution Prevention Plan (PPP) - if the focus is on a particular source or problem (and the scope of an EMS is too broad). A PPP can apply municipality wide, to departments or to individual facilities.
4. Develop a Flow Reduction Plan - this is a type of pollution prevention plan focused on a single problem area, i.e., flows to municipal sewers.
5. Develop a water conservation program. This is a component of a flow reduction program, with additional benefits for water supply system capacity and operation costs.
6. Update sewer use by-law.
7. Develop a community-based social marketing campaign for lot level source control and pollution prevention. This type of program integrates the requirements of the PP and Flow Reduction.
   

Involvement with Others (Pull)

1. Financial and/or technical assistance from other levels of governments should be sought.
2. Carry out watershed planning with conservation authorities, or RAP planning with provincial and federal involvement. These overall plans with their broad and specific objectives are particularly useful for providing the context with specific objectives and targets to apply in other plans (such as PP, EMS, flow reduction) into which PP plans can be meshed or integrated.
3. Empower neighbourhood groups to apply the principles of PP by - neighbour to neighbour campaigning providing information and resources.

Push for Action (Push)

1. Push implementation of PP and Flow Reduction plans at the neighbourhood level with delivery and action oriented education for specific programs; assistance for downspout disconnection programs; application of household hazardous wastes collection programs; water conservation.
2. Enforce by-laws for residential areas, such as litter and animal control.
3. Enforce Sewer Use by-law with active monitoring program, compliance follow-up, and charges when necessary.
4. Use the stormwater provisions in the Sewer Use by-law to require industries to carry out Best Management Practices plans, develop PP or EMS plans, and construct stormwater control works.

By-Law Adoption and Modifications

Identify potential by-laws that could address pollution prevention activities, including: sewer use by-laws; downspout disconnection by-law; water use/conservation; litter control etc. The City of Toronto's Sewer Use by-law (2000) is an example of a by-law that asks for pollution prevention.

Official Plan Policies

Modifications may be needed to enable pollution prevention and flow reduction measures. Goals of these measures could be identified. Watershed planning requirements for existing areas could be identified.

Subdivision Design Policies and Drainage Standards

Modifications may be needed to facilitate pollution prevention and flow reduction measures, stormwater management policy for municipal road and sewer construction projects, and redevelopment projects.

Conclusions

Stormwater management is a challenge to many municipalities because many practices are still evolving and their operation and maintenance costs are not known. The traditional downstream storage and treatment facilities (e.g., ponds and wetlands) are still attractive to many municipalities as they handle flows from large drainage areas and are generally cost-effective. Nevertheless, municipalities should be open minded to new approach where non-structural measures are practised.

References

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