Hydro International experts talk about improving stormwater treatment while keeping environmental and regulatory compliance in mind. 

Why is stormwater treatment and pollution capture so important?

Planning, designing, operating and maintaining stormwater solutions, and improving stormwater capture, is not just about water projects. The success of a stormwater solution scheme is a vital element in securing public health, improving the quality of the environment and improving the livelihoods of those who depend on water for their work.

Stormwater covers a wide variety of water types, including municipal wastewater in some regions. If wastewater isn’t treated correctly, and discharges to surface waters from sewer flows aren’t eliminated of pollution, regions will be at risk of failing to comply with regulation. Many countries have significant and stringent regulations in place surrounding stormwater and its capture and treatment, and it is vital for those tackling this difficult issue to ensure they comply with all local and regional requirements.

What role does flow play in stormwater treatment?

Flow is the most important factor to be considered in managing stormwater. The methodology for managing flow is likely to change, depending on the individual regulatory scheme. Flow management can be achieved by either structural or non-structural means.

The following considerations should always be made about stormwater treatment:

• The quantity of flow that must be managed
• The frequency at which the design flow is predicted to occur
• Where attenuated flows can be detained if they cannot be discharged back into the drainage system

How can I reach a correct specification for a stormwater treatment system?

A suitable specification for any stormwater treatment system includes:

• The correct size
• The right amount of maintenance
• How to achieve maximised returns

To reach the correct specification, engineers must design a solution that matches the requirements of the local regulations. These requirements will inevitably determine the sizing of the solution, and in turn, the costs. All specifications must keep in mind the importance of sustainability. Current practices favour reduction or elimination of site discharges into the municipal drainage system and so each specification must offer an alternative.

In some, although unlikely circumstances, there may be no applicable regulations. To reach the right specification, engineers will need to determine the size of the solution around its ability to treat the bulk of annual pollutant load - without diminishing returns.

How can I maintain my stormwater treatment system, and how important is maintenance?

The penalties of poor stormwater treatment, or a lack of treatment, are severe. The cost is not only financial - it’s reputational as well. External costs also include the loss of environmental services and business and personal impacts. In the most dramatic cases, regulators can halt operations of non-compliant businesses.

Proper, ongoing maintenance can help you to avoid this. Maintenance includes regular inspections, regular cleaning of the equipment, excavation and in some instances repair for general wear and tear. Assessment on capacity should also be reviewed from time to time. Access to the entire pollutant storage zone is also critical for efficient removal or treatment.