Preventing Solids in Storm Drains

A common factor during all storm water inspections is a thorough examination of catch basins. Catch basins, are the initial point of entry into the storm sewer designed to trap solids that would not pass readily through the sewer. This typically takes the form of a cistern with discharge point above the bottom that allows solids to settle.

During our comprehensive inspections, we have noticed that many of our customers have gravel or other settleable solids consistently filling up the catch basins which can allow these solids to pass through to surface water. At some locations, quarterly vacuuming of the catch basins is required.

These pesky solids can come from anywhere such as nearby train tracks, roadway construction, or crumbling pavement. This buildup of solids in your catch basin can cause solids to discharge into the storm sewer, or even block the flow of water completely. The most common cause is the degradation of the pavement around the storm drains, often in high traffic areas such as a loading dock. Frequent traffic, especially during the spring, can erode these areas and allow solids to pass into the downstream storm sewer system.

But how can this be prevented? Unfortunately, asphalt erosion is not an obstacle that can always be easily solved. If the pavement in your yard area erodes quickly and causes blockage in the catch basins, more frequent cleanings or even repaving the area may be necessary. Repaving the worn asphalt is the most practical and long-term fix for this problem, but it can be expensive and time consuming. Other factors may also be affecting how quickly your pavements is eroding. The accessibility of the loading dock and stored equipment may cause trucks to conduct multiple point turns, causing more erosion. If your loading dock is hard to access, you may notice the asphalt in the area wearing away quickly. Reorganizing outdoor storage may help reduce overall traffic in outdoor storage or loading dock areas.

When repaving and reorganization are not viable options, filtration can be used to keep solids from reaching the catch basin. With the use of hydrocarbon filters, solids, oils, and other hydrophobic contaminants will be removed from the storm water at the point of discharge. The filters are easy to change and provide peace of mind for those high-risk drains at your facility. These filters also have an access slot for storm water sampling. We have found that these drain filters are an economic alternative to excessive catch basin preventative maintenance.

CFR has over 30 years of experience in storm water compliance. Give us a call today to see if we can help you with your storm water problems.