As process engineer for this project, Apex Engineering designed and oversaw construction of three biological treatment systems for nitrate and sulfate removal to meet state antidegradation standards. Flow rates range from 6 to 50 gpm, with nitrate-nitrogen concentrations of 6 to 30 mg/L and sulfate concentrations of 100 to 800 mg/L. Project responsibilities included column testing, preparation of engineering reports and O&M manuals for state review, meeting with state scientists and engineers, conceptual design and cost estimation, final design and construction oversight, teaming with other consultants on the project, and start-up and operations support. The selected technology combines engineered reactors and in situ biological treatment.
Here's a paper and presentation on this treatment system:
Completed Underdrain treatment system
Key Mine treatment system under construction
Key Mine system in operation