At the WEF 2013 Conference in October, GAI’s Dr. Manjiang (MJ) Chen, PE received the 2013 Gascoigne Medal for Wastewater Treatment Plant Operational Improvement in recognition of her optimization study and pilot test success in reducing phosphorous and nitrogen at Daytona Beach’s Bethune Point Wastewater Treatment Facility (WWTF).

The problem surfaced at the Bethune Point facility when a 1999 Bardenpho upgrade to achieve advanced wastewater treatment standards did not succeed, and the addition of methanol as a supplemental carbon source in 2004, still did not meet total nitrogen (TN) permit requirements. In 2008, the Florida Department of Environmental Protection (FDEP) sent a warning to the City of Daytona Beach (City) regarding permits on TN and pH discharged from Bethune Point (WWTF), and by 2009, a consent order from the FDEP required compliance, evaluation of new carbon sources for nitrogen biological removal, a pilot test to determine the most viable source, and that permit modification and a preliminary design report be submitted to the FDEP in a timely fashion. Preliminary results of a 2010 pilot test using “MicroC glycerin” as a supplement for the reduction of nitrogen were inconclusive.

Except for treated wastewater in the reuse system, the Bethune Plant pilot study location represents combined discharge from Bethune Point WWTF and Westside Regional WWTF into the Halifax River—GAI’s solution must be comprehensive and long-term.

Between 2010 and 2011, the team “tried different supplemental carbon feed scenarios, including adjusting feed rates to influent flow and loading conditions with the use of continuous on-line nitrate monitoring equipment and supplemental carbon through an automatic feed-forward programmable logic controller (PLC).”

“MJ’s innovative work with the City of Daytona Beach resulted in a cost-effective easily implementable construction, which quickly addressed a Consent Order for the City at both of its wastewater facilities. The implementation of the instrumentation-controlled system lowered the effluent nitrogen even more, and was using less chemicals.”

Jules (Jay) Ameno, PE, Project Manager, GAI

After several attempts, the team tapped into the winning strategy–using “the influent analyzer NOx input signal coupled to the PLC as the primary control, and then the process was trimmed with an additional 10% variance in supplemental carbon feed based on the influent flow signal. The 10% flow-based trimming adjustment provided an additional level of control to help with high-flow conditions.” Consequently, this low-cost strategy led to excellent effluent NOx control across a wide range of operating conditions.

With design finalized, construction of supplemental carbon feed and bulk storage systems at both Daytona Beach treatment facilities will be incorporated into the plant-wide supervisory control and data acquisition systems.

According to Project Manager Jules (Jay) Ameno, PE, “MJ’s innovative work with the City of Daytona Beach resulted in a cost-effective easily implementable construction, which quickly addressed a Consent Order for the City at both of its wastewater facilities. The implementation of the instrumentation-controlled system lowered the effluent nitrogen even more, and was using less chemicals.”


Established in recognition of George Bradley Gascoigne, WEF’s prestigious Gascoigne Award acknowledges individuals who develop and publish an exceptional solution to an important and complicated operational problem within a full-scale operating wastewater treatment plant. The Bethune Point WWTF and MJ’s analyses, solution, pilot study, and her publication, “Optimizing low-level nitrogen removal,” met all criteria.

MJ, Assistant Project Manager at GAI Consultants, specializes in water and wastewater plant operational evaluations, utility system inspection and valuation, preparing engineering reports in support of utility design, permitting and certifications of utility construction, open–surface drainage and pressurized conduit system calculations, surface water control structures flow ratings, and storm water management.

MJ earned her Doctorate at Clarkson University in New York, and is a registered PE in Florida, North Carolina, and South Carolina. MJ, with Gary Johnson (Director of Process Engineering at Environmental Operating Solutions) and James Thurrott (Daytona Beach Utilities Manager of Treatment Operations) wrote “Optimizing low-level nitrogen removal,” published in WEF’s June 2012 issue of WE&T Magazine. The article details how their innovative approach to achieving TN effluent levels and meet NPDES permit requirements succeeded at the Bethune Point WWTF in Daytona Beach.


For more information about this project, contact Jay Ameno at 561.988.2611 or MJ at 412.476.2000.

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