Commercial Building Stormwater Management

Managing a commercial building’s stormwater system can have significant repercussions not just for the property but for the surrounding community and the quality of its water supply.

Stormwater systems are designed to manage the flow of runoff after storms, with the goals of maintaining unpolluted, high-quality water supplies and allowing for the recharging of groundwater stores.

Awareness continues to increase about pollution’s effects on water supplies and aquatic life. As a result, stormwater management practices have responded by evolving away from essentially a gray, concrete-laden funnel to carry away runoff.

Newer management techniques include landscaping and other green features that capture pollutants onsite and allow stormwater runoff to soak in and get purified where it falls. However, commercial properties have challenges that make improving water quality difficult for a few critical reasons.

Commercial Building Stormwater Management—Specific Challenges

Managing a stormwater system entails various activities to capture runoff and filter pollutants. However, commercial systems have some unique challenges that require more in-depth planning and system design.

Consider an average shopping center with vast areas of paved parking lots and acres of ground covered by buildings. These impermeable surfaces prevent stormwater from soaking into the ground where it lands. This water is typically relocated offsite through the stormwater management system’s drains, pipes, and other devices.

Large, paved high-traffic areas such as parking lots collect a lot of leaking oil and other automotive fluids, hydrocarbons, and other vehicle pollutants all day. Some commercial spaces, especially those oriented to consumer entertainment and shopping, have a large volume of trash and debris that constantly collects and makes its way into the drainage system.

Common Commercial Property Issues

Due to the large areas covered by many commercial buildings and complexes, stormwater management typically experiences the same issues as other stormwater systems but on a much larger or potentially more serious scale. With large areas of impervious ground and the resulting water runoff, just one clogged pipe or storm drain can cause a large flooded area, damaging the surrounding buildings, landscaping, cars, and more.

Another critical issue is the level of pollutants contributed by commercial properties. Due in part to a large amount of runoff and a high traffic volume, commercial properties can potentially add large quantities of pollutants, trash, and debris directly into water bodies.

Commercial and industrial properties may also contribute various chemical contaminants to the water supply as by-products of manufacturing and other operations. Stormwater runoff does not go through any treatment, and runoff carries all of these pollutants straight into the water supply.

According to Caltrans, the entity tasked with managing stormwater runoff on California’s roads and highways, the top six pollutants on impermeable roads, commercial parking and camping areas, and highways are as follows:

1. Trash and litter
2. Sediment from eroding gardens and green areas
3. Nutrients from fertilizers and vegetation waste such as fallen leaves
4. Bacteria from pet waste and RVs parking and dumping
5. Metals from vehicles, brakes, and tire wear
6. Pesticides from tree and shrub maintenance
   

Trash and litter, sediment, and organic matter contribute to clogged storm drain and pipes, and all of the above pollutants negatively impact the water supply and the health of aquatic and plant life. The problem seems simple, but so many factors contribute to clogs and pollution that the resolution can become complex and costly.

Solving the Problems

Commercial property owners and managers can do quite a bit to resolve their commercial building stormwater management woes and help their properties contribute less to pollution and improve water quality, and recharge natural water supplies and underground aquifers.

The first step is to repair any broken or degraded parts of the stormwater management system. This task depends on the size of the commercial property and the complexity of its stormwater management system.

The next step involves reviewing and updating a maintenance schedule for the system. Finally, a stormwater system review performed by qualified engineers can identify retrofits and improvements to upgrade the system and keep it in good operational shape for the future. Specific solutions will vary depending on the system’s age, size, complexity, and other factors such as budgetary constraints.

Retrofitting a system can fix past mistakes. It can also include adding new devices to handle runoff onsite such as new or improved filtering, bioretention, and swales to absorb rainwater as it falls and capture pollutants in the soil, rather than letting them run into water bodies.

Poor or infrequent maintenance activities can result in a buildup of trash, sediment, and debris, which can clog storm drains and pipes if not cleared through a regular maintenance schedule. Pipe jetting and other techniques can effectively clear immediate clogs and thoroughly clean pipes to enhance the overall system operation.

Green infrastructure methods are part of the future of stormwater management, and they mimic the natural water cycle. These practices include enhancing landscapes with more trees and grassy areas, adding water features to common areas, using permeable surfaces instead of pavement, and capturing more stormwater with rain barrels and bioretention techniques.

Commercial Stormwater System Best Practices

Commercial building stormwater management personnel can apply some of the same best practices for municipal and private stormwater management systems.

Best practices are often guiding principles, while some are more task-specific. For example, a best practice guiding principle for pollution management is to stop pollution as close to the source as possible. In practice, this involves tasks like frequent street sweeping to remove debris, trash, and organic matter from paved surfaces before the rains come.

Another best practice is to use landscaping to its best advantage. Landscape commercial areas to prevent soil erosion and keep storm drains clear of sediment to keep it from reaching water bodies. Apply pesticides and fertilizers wisely, with the right amounts, and at the right times. Integrate more and larger grassy areas to absorb runoff.

Many other best practices exist for structural, maintenance, and vegetative procedures to treat, reduce, and prevent water pollution. These are system-and property-specific.

CatchAll Environmental Has Your Solutions

Keeping tabs on stormwater system maintenance, compliance, and repairs is complicated. Join the club and learn how the Catch-all system is helping commercial stormwater system managers turn outdated, poorly maintained, or ineffective stormwater systems into efficient, high-performing, and compliant systems.

Catch-All Environmental will show you how to get the system improvements and repairs you need at a cost that makes sense for your budget. Contact Catch-All today!