SWQ control features can be thought of as a filtration system for stormwater runoff from developed property. These can come in many forms as listed below and require special maintenance:
History of Stormwater Quality
Project Storm understands the headaches involved with keeping up to date with maintenance and annual permit renewals. Our goal is to lift that burden off of property owners allowing them to focus on their own businesses and ways of life making the renewal process as simple and low cost as possible.
Our staff of trained engineers and construction managers have extensive knowledge and experience with the City of Houston and Harris County Stormwater Quality Permitting Processes. We handle every aspect of the permit renewal process, from inspections and engineer certification to document preparation and procurement of approved permits.
Our staff is trained in safe inspection practices for dozens of stormwater quality control features.
We renew Wet and Dry ponds, as well as all underground units, inlet filters, and various Trash Seperators.
We have experience writing SWQMP’s
Cleaning and Maintenance
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- Inlet Filter Baskets and Skimmer Boxes
Filter baskets collect the trash, lawn clippings and larger sediment particles typically located in large parking lots. Some varieties of inlet filters come equiped with an absorbent media designed to filter out oils and toxic chemicals that may have been spilled or washed off of vehicles by rainfall. In order to clean a filter basket, the inlet grate must be removed and the contents of the basket removed then disposed of. Fiberglass inlet filters are designed to hold a constant volume of water which can make them quite heavy and difficult to lift. In that event, a vacuum pump or truck is used to remove the water making the filter light enough to lift and clean.
- Oil Grit and Trash Separtators (OGT's)
O/G/T devices are more complex underground systems which use the principles of buoyancy and a series of chambers with high and low bypass points to trap floating oils and sinking sediments allowing clean water to flow out of the unit. Cleaning of OGT devices almost always requires the use of a specialized vacuum truck to pump all of the unit's contents out for disposal at an approved dump site. This process can be expensive due to the cost to operate a vacuum truck and the sheer volume that must be removed (several thousand gallons in most cases). This is why it is crucial for owners to be mindful of any avoidable pollutants or grass clippings that might find their way into the SWQ unit.
- Detention basins
Detention ponds both wet and dry allow rain water to decrease in velocity long enough for sediments, oils and debris to settle out as the water level returns to normal. Vegetation has a remarkable ability to filter and breakdown pollutants on a chemical level and neutralize the toxic characteristics. Man-made trash is removed from the detention ponds during routine grass maintenance on a monthly basis. Many detention ponds are outfitted with restrictors or trash screens that catch any large pollutants slowing the water and allowing more time for particulates to settle out in the pond. The pond will continue to collect sediments until a point at which it does not drain as designed and desilting efforts will be made to restore the pond to its original design.
- Vegetated Grass Swales
Swales are shallow trenches surrounding facilities that direct rainwater to the designated MS4 at a rate that will not overload the waterway. Lawn care practices are used to maintain swales and ensure that outfall pipes do not become blocked as this could lead to flooding.
- Hydrodynamic Vortex Chambers
Hydrodynamic SWQ features work by funneling stormwater in a cylindrical chamber to reduce the velocity allowing heavy particulates to settle out as the water continues through the unit. Clean water leaves the unit while the particulates are left behind. This type of control feature requires a vacuum truck for cleaning as the design requires a large volume of water to be present in the unit at all times.
Following completion of a City or County approved development project, a post-construction certification must be completed to determine whether or not the proposed stormwater quality device was built and installed according to the engineering plans. This action is the first step in activating the stormwater quality permit for that development. Project Storm will recover the original plans and have one of our staff engineers certify if the unit was installed correctly.
Stormwater Quality (SWQ) was first implemented by The City of Houston and Harris county in 2002 as a means to reduce the volume of pollutants reaching our streams, bayous and watersheds. With the increasing development of the greater Houston area, our waterways would would inevitably be overwhelmed with pollutants if not for the SWQ programs.
The SWQ requirements laid out for each property owner are dependent upon the SWQ control feature installed. Control features are selected by the design engineer prior to construction based on the volumetric flow rate they can handle during rain events. The size of the property along with the amount of impervious ground cover determine these values and in turn play a role in the type of SWQ feature needed.
Most property owners are not familiar with SWQ or the management practices used to ensure that their control feature continues to operate as intended. It is also common for property owners to not be informed of the permitted feature or the renewal process once their property is developed.
Our goal is to keep property owners informed with their specific stormwater quality management plan, and make it our responsibility to uphold the maintenance and permit renewal process to keep the owner in compliance.