The purpose of the field test was to determine whether the WTS2000 may be used to decant water from hydrodynamic separators and whether treated water can be discharged to a downstream BMP or any downstream location in the absence of a BMP.
Location
Challenges
The MTD cleaned during the field test is in a campus parking lot. The bottom of the MTD, which contains the majority of the sump material, is approximately 15 feet underground.
Procedure
Starr Water Treatment Systems crew arrived at 10:00 am to set up traffic cones and close off the section of the parking lot where the MTD was located. The WTS2000 was brought into the parking lot and detached from the pickup truck. The manhole covers were removed to expose the Stormceptor Model 7200.
Dr. George Guo of Rutgers University and his team arrived on site and set up all testing materials, including plastic buckets to determine water flow and sample jars placed at specific locations alongside the WTS2000.
The WTS2000 was prepared for BMP cleaning and sample testing. The unit was leveled using the built-in adjustable legs of the trailer and the top lids were removed to observe the system during testing. A submersible pump connected to a 3 inch hose was inserted into the MTD and attached to the influent of the unit. A 4 inch effluent house was also attached.
As the pumping of the dirty water into the WTS2000 began, Dr. Guo and his students began taking and recording samples. A total of five water samples were taken at the influent at approximately 30 minutes apart. A total of five water samples were taken at the effluent correspondingly.
After testing was completed, the manhole covers for the Stormceptor were put back, all equipment was returned to its proper location, and roadblocks were removed. The lids were placed onto the unit and securely fastened. The WTS2000 was reattached to the truck and removed from the site.
Results
The WTS2000 averages an 87.5% TSS reduction rate during MTD cleanouts. We did not experience any clogging during the maintenance process and the unit performed as expected.
Results from the water samples collected during the comprehensive evaluation of the WTS2000 during MTD cleanouts show a positive correlation between the influent TSS concentrations and the TSS reduction rates. This trend can be found across all prior test results for this application. The results are expressed in the chart below:
The trendline demonstrates that TSS concentration and TSS reduction are directly proportional: as TSS concentration increases, TSS reduction increases as well. The TSS reduction capability of the WTS2000 Water Treatment System increases exponentially. The “R2” value next to the trendline quantifies this correlation on a scale of 0 to 1, where an “R2” value of 1 represents an unquestionable correlation. Our “R2” value is 0.9166, showing a strong correlation. This strong correlation helps to prove our theory that as TSS concentration in influent water increases, the TSS reduction capabilities of the WTS2000 Water Treatment System also increases.
Benefits
Following a series of field and lab tests similar to the one at Monmouth University, Rutgers University School of Engineering Department of Civil and Environmental Engineering concluded and recommended that the WTS2000 could be used to decant water from hydrodynamic separators and that the water after treatment could be discharged to any downstream BMP. In the absence of a downstream BMP, the water could be discharged to any downstream drainage location.
The WTS2000 reduces pollutants removed from storm drains, such as hydrocarbons, silt, sand, nutrients, and heavy metals. It also reduces the biochemical oxygen demand and chemical oxygen demand of water as well as prevents TSS from polluting nearby waterways. The WTS2000 eliminates the need to bring stormwater MTD sump water to a wastewater treatment plant for cleaning and returns water to the aquifer free of debris, hydrocarbons, and other pollutants.