NON POINT RUNOFF

 STORMWATER/GROUNDWATER TREATMENT

Nitrogen & Phosphorus Removal

  Contact:  Pio Lombardo, P.E.

Lombardo Associates, Inc.

Environmental Engineers/Consultants

49 Edge Hill Road

Newton, MA  02467

Tel:     617-964-2924

Fax:    617-332-5477

Email: Pio@LombardoAssociates.com

Web Site:  www.LombardoAssociates.com

Technology Description:Based on ten years of research at the University of Waterloo, proprietary patented nitrate and phosphorus reactive media have been discovered that converts nitrate to inert nitrogen gas (denitrification) and binds phosphorus without sludge production. The reactive media is contained in a prefabricated tank or, for larger installations, in an engineered excavation or permeable reactive barrier. Nitrogen and phosphorus contaminated water is gravitationally fed through the treatment module.  A pre-treatment step is required to convert ammonium (NH₄⁺) to nitrate (NO₃^-) before the filter can perform the reductive denitrification step.  No pretreatment is needed for phosphorus removal.  For certain applications with high TSS, pretreatment for solids removal will be necessary.  The very low nitrogen and phosphorus effluent from the Runoff filter is simply discharged to a subsurface dispersal system or receiving water body. Compared to other technologies, the filter is passive and essentially maintenance free. It provides up to 97 +% nitrogen and phosphorus removal in a low cost easy to install process.

Application:

The Runoff filter can be used to remove nitrogen and phosphorus in surface and subsurface water such as stormwater runoff, agricultural runoff, and groundwater. The Runoff reactive media may be placed in a lined excavation, and the water allowed to gravitationally percolate through the reactive media or placed in a subsurface trench as a permeable reactive barrier.

Environmental Benefits:Nonpoint sources of nitrogen and phosphorus are the recognized causes of water quality degradation in many water bodies as the nitrogen and phosphorus are the controlling nutrients for algal growth.  The fertilizing effects of nitrogen and phosphorus have created water quality problems in many coastal and inland areas.  Conventional phosphorus removal technology generally produces tremendous amounts of sludge that must be processed.  Conventional nitrogen removal technologies require chemical addition and on-going maintenance.  The Runoff filter is the only known treatment technology to provide virtually complete single-pass phosphorus and nitrogen removal (97%+) to produce an effluent quality that meets the new stringent surface water discharge criteria.

Performance:The Runoff filter can meet the most stringent nitrogen and phosphorus regulatory criteria. The RUNOFF filter is a low cost, easily installed solution that requires no pumping or chemical addition equipment and is maintenance free for many years after the installation. Over the past six years, numerous installations have been completed in various applications such as for golf courses and farming areas. Overall average removal rates of 90%+ for nitrate (NO₃^-) have been attained.

Limitations:For certain applications, the RUNOFF filter requires oxidative pre-treatment of the water to convert ammonium (NH₄⁺) to nitrate (NO₃^-).  A pre-treatment step is usually not required for agricultural runoff RUNOFF filter phosphorus removal applications. The RUNOFF reactive media is eventually consumed and typically must be replaced in 15-20 + years.

Cost:RUNOFF filter cost are very site / application specific and a preliminary engineering assessment to determine the optimal system.  One of the major attractiveness of the RUNOFF filter is that no ongoing operational or maintenance costs are necessary for either RUNOFF filter applications.  Demonstration projects are recommended to optimize application parameters.