Summit Lake Park, Indiana
Summary
Location: Summit Lake Park, Indiana, USA
Project commenced: June, 2014
Purpose: Wastewater and sewage treatment for National Park
Treatment Volume: 273 m³ / day
About the Project
Summit Lake, Indiana, was a perfect example of the challenges faced by remote communities with highly variable flow, significant distance from established infrastructure and difficulties in getting qualified staff to operate and manage a traditional wastewater facility. The existing wastewater treatment facility was failing to meet the discharge limits set by the EPA and the National Park Authority needed to find a solution that could operate with limited power, be maintained easily by the staff on hand and meet and exceed discharge limits during its operational lifetime.
ALGAESYS was introduced to replace the previous wastewater treatment system. The plant, pictured on the right, was constructed within its own polycarbonate frontage to ensure sunlight was able to reach the reactors within. Additionally, the greenhouse allows for a controlled internal temperature in an open environment where temperatures can usually range from -10 to 30 degrees centigrade. The previous wastewater pump technology was reused, and the new plant was placed adjacent to the old one at the end of the existing sewerage system.
Challenges
The challenge of this project was the combination of the variability and composition of the influent flow. On weekdays, the average load for the treatment plant was the effluent produced by eight resident park rangers. During the weekend and holiday seasons, the parks’ population grows to encompass approximately 350 recreational vehicles. The recreational vehicles empty their chemical toilets into the intakes for the plant along with their grey-water tanks and any other liquid or semi-liquid foodstuffs. This variation in flow and toxicity would typically cause significant problems for a traditional wastewater treatment plant, as evidenced by the inability of the existing plant to meet discharge limits, however, our treatment solution deals with flow variation much better than typical treatment processes due to its self-balancing nature.
Effluent testing results:
Parameter: Actual result (Trigger value)
BOD5 (mg/L): 6 (20)
NH4-N (mg/L): 0.4 (1)
SS (mg/L) : 7 (20)
CFU (/100mL): 940 (1000)
Performance
The plant was constructed and commissioned within 12 weeks and began operating in June 2014. Initially, as the technology was considered ‘novel’ by the Indiana Department of Environmental Management (IDEM), the water was run through the existing wastewater treatment plant and then through the ALGAESYS plant to reduce any risk of exceeding discharge limits. Additionally, IDEM imposed the following discharge limits. BOD5 of 20mg/L, NH4-N of 1mg/L, SS of 20mg/L and CFU of 1000/100mL. Once the plant went into operation and consistently outperformed the discharge requirements, IDEM halved all limits except the CFU count. In all of the years of operation, the plant has never failed to meet the permitted discharge limits while remaining below the designed flow rate.
Maintenance and Operation
One of the main benefits of the ALGAESYS system is its’ ability to be maintained by any operator. The park rangers were given an introductory course into how the plant works and operates and how to maintain it. The plant only requires approximately 3 hours of management per week by the rangers. These 3 hours account for the duration required to conduct the water quality testing using a mobile kit. Activities outside of the water quality testing are limited to checking the levels on the solids tank, cleaning weirs, checking the rotation of the logs (sometimes get stuck by a build-up of water snails), general cleaning and the need to put excess biomass outside on a drying table.
Due to the simplicity of the plant design and the flexibility of the bio-remediation system, it is almost entirely autonomous and does not require continuous monitoring or adjustment to maintain treatment efficacy. Combined with the minimalistic power use due to the non-mechanical nature of the method used for log rotation and water flow, ALGAESYS is an incredibly safe, robust and simple plant to operate.
Improvements
Summit Lake Park is our longest-standing treatment plant and continues to operate today. Since its implementation in 2014, we have continued to improve how ALGAESYS works by developing the plant design, improving efficacy and reducing the carbon footprint of our plant operations. We now construct the bioreactor tanks out of 345 Stainless Steel (reducing the carbon footprint compared to pre-cast concrete tanks), which has a longer operational lifetime and the ability to re-use/move plants in the event they are no longer needed in the original commissioning location.
We now make the logs out of gas entrained polypropylene, which results in 15% lighter logs, less energy and material required to produce them, less cost and weight for shipping, less energy required to rotate them (in operations) and it also delivers a “pitted” surface which allows the organisms in our bio-reactors to attach better and reduces our commissioning times. The results of these developments, combined with the perfection of our process, means that we now routinely produce the results shown here (with no chlorine dosing or UV Filtration).
