Contech CatchBasin StormFilter Operation And Maintenance

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Stormwater Solutions from Contech
CatchBasin StormFilter™
Important: These guidelines should be used as a part of your site stormwater plan.
Overview
The CatchBasin StormFilter™ (CBSF) consists of a multi-chamber steel, concrete, or plastic catch basin unit that can contain up to four StormFilter cartridges. The steel CBSF is offered both as a standard and as a deep unit.
The CBSF is installed flush with the finished grade and is applicable for both constrained lot and retrofit applications. It can also be fitted with an inlet pipe for roof leaders or similar applications.
OPERATION AND
MAINTENANCE
Once in the cartridge chamber, polluted water ponds and percolates horizontally through the media in the filter cartridges. Treated water collects in the cartridge’s center tube from where it is directed by an under-drain manifold to the outlet pipe on the downstream side of the overflow weir and discharged.
When flows into the CBSF exceed the water quality design value, excess water spills over the overflow weir, bypassing the cartridge bay, and discharges to the outlet pipe.
The CBSF unit treats peak water quality design flows up to 0.13 cfs, coupled with an internal weir overflow capacity of 1.0 cfs for the standard unit, and 1.8 cfs for the deep steel and concrete units. Plastic units have an internal weir overflow capacity of 0.5 cfs.
Design Operation
The CBSF is installed as the primary receiver of runoff, similar to a standard, grated catch basin. The steel and concrete CBSF units have an H-20 rated, traffic bearing lid that allows the filter to be installed in parking lots, and for all practical purposes, takes up no land area. Plastic units can be used in landscaped areas and for other non-traffic-bearing applications.
The CBSF consists of a sumped inlet chamber and a cartridge chamber(s). Runoff enters the sumped inlet chamber either by sheet flow from a paved surface or from an inlet pipe discharging directly to the unit vault. The inlet chamber is equipped with an internal baffle, which traps debris and floating oil and grease, and an overflow weir. While in the inlet chamber, heavier solids are allowed to settle into the deep sump, while lighter solids and soluble pollutants are directed under the baffle and into the cartridge chamber through a port between the baffle and the overflow weir.
Applications
The CBSF is particularly useful where small flows are being treated or for sites that are flat and have little available hydraulic head to spare. The unit is ideal for applications in which standard catch basins are to be used. Both water quality and catchment issues can be resolved with the use of the CBSF.
Retro-Fit
The retrofit market has many possible applications for the CBSF. The CBSF can be installed by replacing an existing catch basin without having to “chase the grade,” thus reducing the high cost of re piping the storm system.
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Page 1
www.ContechES.com/stormwater
800-338-1122
© 2013 Contech Engineered Solutions
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Stormwater Solutions from Contech
CatchBasin StormFilter™
OPERATION AND
MAINTENANCE
Maintenance Guidelines
Maintenance procedures for typical catch basins can be applied to the CatchBasin StormFilter (CBSF). The filter cartridges contained in the CBSF are easily removed and replaced during maintenance activities according to the following guidelines.
1. Establish a safe working area as per typical catch basin service activity.
2. Remove steel grate and diamond plate cover (weight 100 lbs. each).
3. Turn cartridge(s) counter-clockwise to disconnect from pipe manifold.
4. Remove 4” center cap from cartridge and replace with lifting cap.
5. Remove cartridge(s) from catch basin by hand or with vactor truck boom.
6. Remove accumulated sediment via vactor truck (min. clearance 13” x 24”).
7. Remove accumulated sediment from cartridge bay. (min. clearance 9.25” x 11”).
8. Rinse interior of both bays and vactor remaining water and sediment.
9. Install fresh cartridge(s) threading clockwise to pipe manifold.
10. Replace cover and grate.
Mosquito Abatement
In certain areas of the United States, mosquito abatement is desirable to reduce the incidence of vectors.
In BMPs with standing water, which could provide mosquito breeding habitat, certain abatement measures can be taken.
1. Periodic observation of the standing water to determine if the facility is harboring mosquito larvae.
2. Regular catch basin maintenance.
3. Use of larvicides containing Bacillus thuringiensis israelensis (BTI). BTI is a bacterium toxic to mosquito and black fly larvae.
In some cases, the presence of petroleum hydrocarbons may interrupt the mosquito growth cycle.
Using Larvicides in the CatchBasin StormFilter
Larvicides should be used according to manufacturer’s recommendations.
Two widely available products are Mosquito Dunks and Summit B.t.i. Briquets. For more information, visit http://www. summitchemical.com/mos_ctrl/d efault.htm.
The larvicide must be in contact with the permanent pool. The larvicide should also be fastened to the CatchBasin StormFilter by string or wire to prevent displacement by high flows. A magnet can be used with a steel catch basin.
11. Return original cartridges to Contech for cleaning.
Media may be removed from the filter cartridges using the vactor truck before the cartridges are removed from the catch basin structure. Empty cartridges can be easily removed from the catch basin structure by hand. Empty cartridges should be reassembled and returned to Contech as appropriate.
Materials required include a lifting cap, vactor truck and fresh filter cartridges. Contact Contech for specifications and availability of the lifting cap. The vactor truck must be equipped with a hose capable of reaching areas of restricted clearance. the owner may refresh spent cartridges. Refreshed cartridges are also available from Contech on an exchange basis. Contact the maintenance department of Contech at 503-258-3157 for more information.
Maintenance is estimated at 26 minutes of site time. For units with more than one cartridge, add approximately 5 minutes for each additional cartridge. Add travel time as required.
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For more information on mosquito abatement in stormwater BMPs, refer to the following: http://www.ucmrp.ucdavis.edu/ publications/managingmosquitoesstormwater8125.pdf
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www.ContechES.com/stormwater
800-338-1122
© 2013 Contech Engineered Solutions
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