Stormwater treatment options such as pretreatment, post-treatment, oil water separators and sandfilters are available as a stand-alone system, as well as integrated with Storm Capture.

Oil Water Separators

Contamination of our water resources with hydrocarbons is an especially difficult problem to solve because of the widespread use of petroleum products. Oldcastle Precast offers two styles of oil water separators to intercept hydrocarbons in stormwater runoff, the generic baffled style for lower concentration areas, and, for hydrocarbon "hot spots" we provide separators that use enhanced coalescing plate technology and gravitation separation to improve the separation process and reduce the frequency of maintenance and cleaning.

Treatment Treatment
Other Treatment BMPs

Oldcastle manufactures a variety of hydrodynamic separators for pretreatment, as well as a full line of filter systems for advanced treatment. Many of these treatment BMPs can be fully integrated within the Storm Capture system.


We provide Installation and Operation & Maintenance Manuals.


Sandfilters are proven technology that effectively removes pollutants from stormwater runoff after construction has been completed on a given site. Sandfilters are typically triple-chambered structures. The first chamber serves to pretreat the stormwater by allowing larger sediments to settle out and trapping some floatables. Pretreatment is critical in reducing maintenance frequency by removing some of the larger pollutants so that the filter bed will not become clogged quickly. The second chamber contains a filter bed comprised of sand, or other filter media, that will filter out finer particles and other pollutants. The third chamber is a clear well chamber for cleaned water prior to discharge. Each filter can be sized to match your application, thereby making best use of site conditions and providing best options for more efficient maintenance. Oldcastle offers both perimeter-style (at grade) and underground sandfilters. Our sandfilters feature a high-flow by-pass option and comply with underground structure requirements. Most can be installed in one day.

Sandfilters Perimeter Sandfilter
Typical pollutant percent removal rates for sandfilters listed by the U.S. EPA are:
  • TSS 65-90%
  • TP 40-85%
  • TN 44-47%
  • Metals 25-90+%
  • Bacteria 55%
U.S. EPA Technical bulletin on Sandfilters