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Stormwater Pretreatment: Getting More From Your Stormwater Systems

Stormwater pretreatment is a cost-effective way to reduce pollutants in stormwater runoff and benefit from long-term cost savings, giving your facility the keys to meeting local regulations, overcoming design challenges, and maximizing your infrastructure ROI.

Unique Benefits of Stormwater Pretreatment


One of the most effective methods for preventing clogging and system failure is separation. This involves the removal of large trash and debris, sediment, and certain levels of suspended solids, oils, metals, and other contaminants from stormwater before it enters the principal system. Separation is also the preferred method because it can be used in both large and small systems.

Preventing Sedimentation

Sediment in a treatment tank or basin is one of the most common causes of treatment system failure. Sedimentation occurs when solid particles settle out of the water and form deposits on the bottom or sides of basins or tanks. As these deposits build up, they reduce available volume and interfere with function, resulting in inefficient operation.

Maintenance Access

Maintenance and inspection crews love efficiency and easy-access chambers. Pretreatment allows the design of consolidating access and easier manned or equipment-cleaning access, greatly reducing maintenance and management costs.

Photo: Above ground, unmanned entry saves time and money.

Saving Land or Minimizing Footprint

Land use design considerations and efficiency are a high priority for any new development or redesigned property. Implementing pretreatment into a system can give engineers, designers or architects more versatility and options in their efforts to save land or build infrastructure. To accomplish this, pretreatment consolidates the needed areas for trash or sediment collection away from volume control devices or specialized treatment devices, giving designers more flexibility.

Stormwater Pretreatment for Municipal Managers

Pretreatment Device Example:

Catch Basin Inlet Filter

A pretreatment design can help municipalities save money and meet many of their challenging stormwater goals according to state TMDLs and national stormwater pollutant standards (NPDES).

It allows city managers and crews to combat a lot of potential challenges with simple maintenance schedules and routines; preventing many of the problems that cause stormwater pollution or system failure.

Stormwater Pretreatment for Property Owners

Pretreatment Device Example:

SciCloneX Separator

Addressing stormwater runoff provides significant benefits for owners, operators and communities as well. Pretreatment is the best way to prevent clogging and failure which lead to flooding and potentially catastrophic damage. Simply put, pretreatment can help protect your property and dramatically expand design options; saving space and land.

Owners will also see value around lower long-term maintenance demand i.e., lower long-term costs. It also provides superior pollutant treatment, allowing owners to meet strict local stormwater requirements.

Stormwater Pretreatment Advantages for Engineers

Civil engineers and stormwater engineers are often presented with the greatest challenges. Oftentimes, they are responsible for meeting budgets, design criteria, and regulations or stormwater requirements. However, pretreating stormwater can give engineers a great starting point or foundation for designing a complex stormwater management system that will help comply with regulations, but also exceed the expectations of their customers and clients.


There are many goals and challenges when designing a comprehensive stormwater management plan. Integrating pretreatment designs or employing systems with innate pretreatment offers endless benefits to municipal stormwater leaders, engineers, designers, and property owners.