A unique earthworks project to create various ponds to establish an Enhanced Pond System (EPS) to create state-of-the-art technology for wastewater treatment and algal production in high rate algal ponds (HRAP) and integration of HRAP with anerobic primary treatment and energy recovery using a covered anaerobic pond (CAP), and final effluent polishing using maturation ponds and a rock filter.
Two 1ha HRAP were constructed in the area of an existing wetland at the Cambridge Wastewater Treatment Plant. Works included earthworks, embankment protection (compacted earth with a 2:1 slope, protected with non-woven geotextile cover), baffles, (constructed from half round posts and corrugated iron sheet), paddleworks, (the wastewater is mixed around each HRAP raceway using a 6m width paddlewheel with a 2.5Kw variable speed drive motor that is mounted in a concrete lined paddlewheel station), C02 addition, (each HRAP has two central concrete lined 1.5m deep CO2 addition sumps with a variable position baffle that spans across the pond channel width and majority of the pond and sump depth for carbon addition to enhance algal growth using biogas from the algal digester pond).
Additional to the HRA ponds the following ponds/filters were created:
- Algal Harvester Pond
- Algal Digester Pond
- Sand Filters
- Maturation Pond
- Rock Filters
- Habitation Pond (native fish habitat pond)