In 2008, Brinjac Engineering Inc., retained municipal engineer for Wiconisco Township wastewater treatment plant (WWTP), assisted the Township with obtaining Growing Greener II Innovative Wastewater Treatment Grant Award for $84,000 to reduce treatment plant carbon footprint. With this prime objective and considering other aerators related operational issues, the plant was upgraded with new solar circulators/aerators in March'09, with one (1) solar unit installed in Lagoon # 1 and two units (2) in Lagoon # 2. Four (4) of the existing eight (8) aerators were continued to use as backup for these solar units. With these upgrades, the WWTP process changed from aerated lagoons to a system resembling towards an advanced facultative system. System performance was analyzed prior to and after upgrades. During the one (1) year of WWTP operations after upgrades (Mar'09–Feb'10 period), it was in full compliance with NPDES effluent permit. The WWTP influent data indicated that hydraulic and organic loadings remained consistent prior to and after upgrades (Jan'08–Feb'10 period). Average daily effluent BOD5 and TSS were 5.4 mg/l and 29.2 mg/l respectively before upgrades, whereas they were 6.5 mg/l and 18.6 mg/l respectively after upgrades indicating improvements in TSS removal. Average monthly fecal coliform between Jan'08–Mar'09 period was 16 mg/l (prior to upgrades) whereas it averaged at 5.5 mg/l after upgrades reflecting better coliform treatment. Other parameters including D.O., pH and residual chlorine remained within permit limits. Sludge depths in lagoons # 1 and # 2 decreased by approx. 2.50 ft and 0.50 ft respectively after upgrades. In 2009, the SolarBee® units reduced algae sufficient enough that no biological additives were needed for its control, resulting in an annual saving of more than$5,000. Apart from process improvements, monthly electricity consumption and electric bills at WWTP decreased by about 47% and 32% respectively after upgrades. Some additional cost savings were compensated due to increase in unit electric costs. During Jan'08–Feb'10 period, Chapter 94 Reports did not indicate for any significant modifications at WWTP other than Solar system upgrades that would result in major changes to electricity consumption. Hence, energy savings were considered to be directly related to these upgrades. With energy savings, carbon footprint of WWTP decreased by 47%. Process improvements at the WWTP were consistent with experiences from previous case studies. Overall, solar units provided efficient circulation and mixing in lagoons while maintaining aerobic conditions necessary for treatment and served as a suitable option for process improvements, minimizing energy costs, carbon footprint reduction and meeting permit limits.

This content is only available as a PDF.