Installing a Stormwater BMP is an important step towards protecting our waterways, but for them to perform as designed, they must be maintained regularly.
Where do we dispose of the material removed from catch basins and stormwater treatment systems after maintenance? I get that question regularly from both private and municipal maintenance crews. It’s an important question. After all, handling this waste responsibly is the crucial final step in a BMP’s mission to protect our waterways.
Local regulations and system design both play a key role in how waste components are collected and disposed of. For purposes of this discussion, I’m going to break stormwater BMP waste down into two key components; solids and liquids.
From a basic system design standpoint, let’s consider that some BMP’s have the ability to drain down, or dry out, leaving only solids like sediment, trash, and organics to be removed from the system. Others have a permanent pool and as such, retain liquids (water and oils primarily) along with solids. In some cases, these can be removed from the system separately, but frequently these waste components are collected in a single operation, resulting in a mixed load for the maintenance crew to dispose of.
For municipal customers, this usually means setting up an area where the mixed load can be dewatered. The water will separate from the solids and end up at the wastewater treatment plant. The solids will be taken to landfill, often mixed with street sweepings and other waste they regularly collect and dispose of. Mixing with sweepings also provides a quick means of drying the load out. Testing of the water and solids may, or may not occur frequently, based on the wastewater treatment facilities capabilities, and the landfill utilized.
For private entities performing BMP maintenance, some local municipalities will contract the use of their facility for stormwater waste. In other cases, the most convenient means of disposal is utilizing a local industrial waste disposal facility. These facilities are equipped with the technology and expertise to test, separate, and responsibly dispose of mixed loads (liquids and solids). In addition to stormwater waste, these facilities may work with waste streams generated from hydro excavation, manufacturing facilities, car washes, food and beverage processors, and septic waste.
Our stormwater maintenance support staff recently toured one such facility in Portland Oregon where the testing and disposal process was explained. With an onsite lab, they test and profile waste as it enters the facility. This allows them to ensure the waste is within the treatment facilities capabilities. From there, they separate the water and solids, and send the water through their onsite treatment plant. Solids are sent to the landfill, and clean water is discharged per their local Bureau of Environmental Services permit guidelines.
Proper handling and disposal of waste from these systems is an essential part of the treatment cycle. Entities that improperly handle waste may be undoing the work the BMP has been doing between maintenance cycles. Facility owners and municipal program managers can do their part by asking maintenance operators about the process used to handle waste, to ensure pollutants are properly disposed of.
We’d like to know more about the process being used in your area.
Would you take a moment to fill out a 5-question survey to help us better understand disposal practices near you? Click here to take the survey.
You may do so anonymously, however if you’re curious too, we’d be happy to share the results with you if you provide your email address within the survey.