Performance History and Discussion
The wastewater treatment facility for the Homestead Village apartment community treats about 115,000 gallons per day of wastewater for discharge into onsite infiltration lagoons. The facility is required to remove nitrogen from the wastewater to less than 10 mg/L before discharging into the ground. The facility struggled to consistently meet this requirement. 8 out of 10 effluent water samples tested for total nitrogen between January 1, 2010 and November 30, 2010 did not satisfy the facilities permitted requirements. The plant was placed under consent order and a preliminary solution was proposed to construct an additional clarifier. The construction of an additional clarifier was cost-prohibitive to the facility so an interim solution of collection system bioaugmentation was started, which has so far shown promise as a permanent solution to enhancing the removal of nitrogen from the wastewater.
The company that operates the wastewater treatment facility takes measures the effluent nitrogen balance (ammonia, nitrate & nitrite) two times per week using on site analytical tests. Additionally, the plant effluent was historically tested once per month by a local certified lab for total Kjeldahl nitrogen, nitrate and nitrite. During the trial period, the frequency of analysis by the certified lab was increased to once per week to gain confidence in the trial results.
Early results were inconsistent due to multiple equipment failures at the facility: in early 2011 the methanol feed equipment failed and was not repaired until early March, at which time the blowers supplying air to the equalization tank and aeration basins were not supplying enough air to complete nitrification. Further, in late April, the equalization basin was taken offline for cleaning which significantly disrupted plant operation. An analysis that includes the data obtained during these disruptions still shows significant improvement over pre-treated conditions.
The evaluation of collection system bioaugmentation at the Homestead Village facility is ongoing in order to gain a greater understanding of the treatment's effect on the process. The impact of In-Pipe's treatment is significant, however, the verification of the technology will continue for a year in order to demonstrate performance over all of the seasons. Preliminary results are promising, suggesting that the facility will most likely be able to avoid constructing a very expensive clarifier, and instead continue with the In-Pipe Technology collection system bioaugmentation program to enhance nitrogen removal in the wastewater treatment process.
Project Installed: November 2010
Plant Size: 0.10 MGD
- Improve Nitrogen Removal
- 34% Reduction Effluent TN
- 24% Reduction Influent BOD
- 16% Reduction Effluent BOD
- 12% Reduction Effluent TSS
Financial Payback: IPT under evaluation as alternative to $750,000 capital improvement.