Understanding Stormwater Management

Stormwater is water that results from storms that forms a “runoff” into local drainage systems. To understand concerns about stormwater, it is necessary to visualize the actual traverse of stormwater.

Many large businesses have holding ponds that retain excess fluids and liquids used in their processes. When there are no holding ponds, chemicals used may be stored on the property in the same way homeowners store various landscaping chemicals in lawn sheds.

Over time, these chemicals leach into the soil during storms and create toxic or hazardous plumes on the surface or in groundwater. For example, a local dry cleaner may store empty dry cleaning chemicals in a trash can. Moisture from storms eventually causes a certain amount of leaching from the storage container into the soil beneath it. A rain event will spread the leachate into the soil underground where it may eventually end up in water aquifers used for drinking water.

Stormwater Best Management Practices

Each locality sets local standards for stormwater best management practices that comply with their county, state and federal agencies. Most of these practices depend on the potential for stormwater pollution.

In the event the locality has significant sources of potential stormwater pollution, a stormwater pollution prevention plan (SPPP) may be required from each source of potential pollution. In most municipalities, the source or business is responsible to design and implement this plan and keep it updated on an annual basis.

Businesses located closest to local ponds, streams, lakes and rivers are required by federal law to maintain stormwater pollution prevention plans required by the Clean Water Act. Generally, these plans must be authenticated by a licensed environmental or regulatory consultant known as Professional Engineering (PE).

Remediating Stormwater Pollution

In order to control stormwater pollution that exceeds the property line, a drainage system design is required. The drainage system design should include the first outfall source of stormwater to the final outfall. This helps the municipality, county, state and federal agencies identify existing pollution or probable source of stormwater pollution and allows for testing and monitoring of stormwater outfalls.

The drainage system design may be drawn by professional mechanical engineers with the aid of chemical engineers who determine the type of hazardous or toxic pollutants that pose a threat to the municipality’s drinking water and soil. The mechanical engineers create a “model” of the design and chemical engineers review effects of the drainage system’s design on surface and groundwater to ensure it results in compliant levels of water quality.

Water as an Asset

To most individuals, water is a necessity for human life. However, in some municipalities, water is an asset when it is in abundance and is sold to neighboring towns. Specific water value is determined by water quality.

In stormwater management, asset maintenance is part of the plan to retain the highest value of the municipality’s water as a major asset. Asset maintenance for stormwater pollution and prevention may include:

. Updating and maintaining a list of existing and potential stormwater pollution sites

. Regularly scheduled stormwater monitoring and testing

. Requiring regular testing of surface and groundwater

. Providing reports to the community on water quality

Another part of asset maintenance is plan asset hydrologic modeling. This begins with a determination of the hydrological integration of groundwater and surface stormwater created in a graphical model.

Reasons Communities Need a Stormwater Management Plan

The cost of water treatment to restore water quality is a burden borne by residents in each community. With a proper stormwater management plan in place, municipalities save on the cost of energy required to operate water treatment facilities. Seek the services of professional environmental consultants to make the best stormwater management plan based on local water quality data.

About the Author : Delan is a writer at Renew Solutions, an Australian based company who help people in the design or redesign of existing or intended stormwater assets.