IMPROVING STORMWATER QUALITY

Introduction

Contaminated storm water runoff from industrial sites, such as natural gas plants, oil refineries, pulp & paper mills and wood product mills, manufacturing plants, and facilities can produce very high strength wastewater unacceptable for direct discharge to the environment or to municipal wastewater treatment plants. Winter snow accumulation in addition to spring and summer rainfall result in dramatic peak flows which can contain high concentrations of organics nutrients, hydro-carbons, salts, and metals. Direct untreated discharge to environmentally sensitive waterways or municipal sewage treatment plants can cause significant environmental, operation and treatment concerns.

Many industrial facilities use storm water collection ponds to facilitate settling prior to discharging runoff to the environment or municipal sewer system. These are typically anaerobic (producing noxious odors) and well below their treatment potential.

Solution

Incorporating combinations of PNW technologies such ADS fine bubble aeration, Bacta-Pur® bioaugmentation and Aquamats® biofiltration technologies to reduce solids, BOD, COD, metals and ammonia concentrations prior to discharge is a Best Management Practices (BMP's) to manage flows and treat industrial runoff collection ponds reducing environmental impacts and stress to local sewage treatment facilities.

Performance

Re-routing runoff flows, interconnecting existing ponds and implementing PNW treatment technologies to facilitate in-series treatment was effective in reducing industrial wood processing leachate from 5000 mg/L to less than 200 mg/L BOD5.