On SWPPP Storm Drain Inlet Protection

There are a few specific components of many sites that need to be protected when it comes to stormwater pollution prevention plans (SWPPPs) and their management, and storm drain inlets are great examples. Referring to any locations where surface water can enter a stormwater collection system that discharges into any kind of regulated body of water, storm drain inlets require protection from contamination as part of many SWPPP setups. 

At Silver Leaf SWPPP, we're here to assist clients around Utah with all their SWPPP needs, from BMP installation and maintenance to SWPPP inspections, dewatering services and more. Storm drain inlet protection is a common practice we help clients utilize and remain in compliance with, and we're happy to explain the details to anyone new to this area. Here are some basics on the role storm drain inlet protection plays in SWPPP setups, the kinds of inlet protection options available, and more. 

Purpose of Storm Drain Inlet Protection for SWPPP

Simply put, the primary purpose of storm drain inlet protection is keeping sediment and other pollutants out of the nearby stormwater collection system. Storm drains are meant to convey only clean water, but without proper protection, they can easily become contaminated by any number of potential sources on development sites.

But why does this matter? For starters, if a storm drain becomes contaminated with soil sediment or chemicals from construction activities, this can be released into nearby regulated bodies of water like rivers or lakes. This is a major no-no, not only for environmental reasons but also because it violates various local and state regulations. Not only do you not want to be responsible for any such violations, but you also don't want to delay your project and waste resources on cleanup efforts if a storm drain contamination issue is discovered. 

Types of Inlet Protection

There are several commonly used methods for protecting storm drain inlets from contamination:

1. Sediment barriers: These are temporary structures installed around the perimeter of storm drain inlets, designed to filter out sediment and other particulates while still allowing water to flow into the drain.
2. Gravel bags: These devices contain gravel that traps sediment from runoff before it reaches the storm drain inlet.
3. Silt fences: These are barriers made of geotextile fabric, supported by posts or stakes and buried underground to trap sediment before it reaches the drain.
4. Catch basin inserts: These are mechanical devices that fit inside catch basins and filter out sediment before it enters the stormwater collection system.
5. Drain inlet filters: These are similar to catch basin inserts, but they attach directly to the inlet grate rather than fitting inside a catch basin.

Keep in mind that these aren't exhaustive lists - there are many variations and combinations of these methods, depending on the site and its specific needs. 

NOT a First Line of Defense

One extremely important element to be aware of here: Storm drain inlet protection is not meant to be the first line of defense against stormwater pollution. Rather, it should be seen as a secondary option for catching any contaminants that may have slipped through other BMPs (Best Management Practices) already in place. 

For example, let's say your project has installed perimeter sediment barriers and silt fences to control erosion and runoff - both great first-line BMPs. But what if a heavy rainstorm comes through and overwhelms these protections, allowing sediment to reach the storm drain inlet? This is where having secondary protection in place can save you from potential violations and other problems.

Potential for Ponding and Importance of Area Selection

When operating properly, there are times where storm drain inlet protection setups will create ponding of water around the inlet itself. This is normal and should be expected, as these systems are designed to temporarily hold back water in order to filter out contaminants.

However, it's also important to note your storm drain inlet protection system should not create ponding that extends beyond the immediate area of the inlet - if this occurs, it means your setup isn't working properly and needs to be revisited. At Silver Leaf SWPPP, we can help you with both selecting the right areas for storm drain inlet protection and ensuring they're functioning as intended at all times.

Storm drain inlet protection is a key element of many SWPPP setups, designed to prevent pollution from reaching nearby regulated bodies of water through contaminated storm drains. Several types of inlet protection devices are available, but it's important to remember this is a secondary line of defense and must be paired with other BMPs as well. 

For more on any element of SWPPP management or our services for clients around Utah, speak to the staff at Silver Leaf SWPPP today.