In addition to pressure on sewer collection networks, the additional population growth places pressure on existing treatment facilities to increase capacity, and often improve effluent quality.
Consider a 15,000 PE SBR (Sequencing Batch Reactor) facility serving a small town in the UK. With the facility close to capacity, the local utility sought a solution that could double the existing treatment capacity while still being cost-effective, reliable, and sustainable. In addition, the utility received many complaints from nearby residents about odor issues and the site’s poor aesthetics. The ideal solution would resolve the capacity limitations, require limited space in order to do so, and also address the community’s concerns.
The utility initially considered converting the four lane SBR process to a conventional activated sludge process by constructing final settlement tanks, a RAS (return activated sludge) system, and four additional trains (in order to double capacity). However, while this option would allow for the current system to meet the increased capacity demand, it would not solve neighborhood issues stemming from the facility’s large “psychological footprint” (unappealing aesthetics and odor issues). In fact, it would have probably exacerbated the problem! Further, the conversion to an activated sludge plant would require additional land due to the considerable physical footprint involved, including the need for a buffer zone around the facility to address odor issues and poor aesthetics.
As an alternative, the utility looked at an Organica solution. By working closely with the utility to collaboratively come up with a solution, Organica was able to design a facility that would be able to maintain the same physical footprint as the existing facility, while significantly reducing the buffer zone by eliminating the “psychological footprint” and improving the site’s economics through reduced capital and operating costs. The lower capital investment (US$600,000 savings) and operational costs (approximately US$200,000 annual savings) provided by Organica over the activated sludge process was projected to improve the economic return on a net present value basis by approximately US$2,200,000 over 20 years. Further, the Organica solution would create an aesthetically-pleasing, odorless botanical garden in the community – bringing a multitude of benefits that is too difficult to quantify financially, but undoubtedly invaluable for community relations.
In contrast to the proposed SBR solution, the Organica solution offers numerous advantages:
Assumptions: OPEX for both Organica and the alternative wastewater treatment option are assumed to increase at an annual rate of 3%. NPV is calculated over a 20-year time frame using a 5% discount rate.
Disclaimer: Financial estimates used are based on a proposal for a retrofit project in the UK. Images are sample displays. This case study is created for informational purposes only, and should not be considered as a quote or offer of any kind. Financial data, OPEX, CAPEX, actual footprint, components (including but not limited to water reuse functionality), etc. may vary per project depending on the actual requirements.
Use our WWTP Design Generator to plan and compare multiple wastewater treatment plant options in 3 easy steps