Nutrient Removal

Pennsylvania established limits on Nitrogen and Phosphorus, two critical nutrients that are harmful for aquatic life, for larger wastewater treatment plants that discharge anywhere in the Chesapeake Bay Watershed.  Larger treatment plants and small wastewater systems received an annual cap loading for pounds of Total Nitrogen and pounds of Total Phosphorus discharged, along with the manual on wastewater modeling. Mr. Bassett has authored numerous magazine articles and presentations on Nutrient Removal. The nutrient removal upgrade of the Altoona Westerly WWTF won the 2013 AAEES Superior Achievement Award

Bassett Engineering specializes in Nutrient Removal Technology (NRT). We have designed more NRT Systems than any other firm throughout central Pennsylvania. Mr. Bassett is a DEP certified NRT instructor with 20 years of operator training and process modeling experience. He also co-authored two editions of the Water Environment Federation’s manual “Biological and Chemical Systems for Nutrient Removal.”

Mr. Bassett began designing NRT Systems in 1986 in Maryland, and he was the project manager or engineer on 12 NRT upgrades, with design flows from 1.0 to 98 mgd. For a number of years, all have been achieving Nitrogen and Phosphorous levels at or below the 6.0 MGD TN and 0.8 MGD TP levels DEP is now mandating. Bassett Engineering currently has nine WWTPs removing nutrients, and has completed many feasibility studies for NRT implementation. Some representative projects include the following.

Key: HBSF = Hybrid Bardenpho with Step Feed, Ox Ditch = Oxidation Ditch, MLE = Modified Ludzak-Ettinger, VIP = Virginia Initiative Plant, SBR = Sequencing Batch Reactor, IFAS = Integrated Fixed Film Activated Sludge, J.B. = Johannesburg, A₂O = Anaerobic/Anoxic/Oxic

For treatment facilities, investing in NRT can be profitable. Pennsylvania allows Nutrient Credits to be traded; it has established a formal trading program through PENNVEST, plus parties are also able to buy and sell credits directly.  Any treatment facility whose discharge of Nitrogen or Phosphorus is less than its annual cap loading can sell credits.  Other entities can also generate credits, for example farmers who implement best management practices to reduce their nutrient discharges.  Credit generators can sell credits to any needy buyer – another Authority or a developer – either directly or through the exchange.

Click here to read Bassett Engineering’s article on nutrient removal which was published in “The Authority” and “The Borough News” Magazines.