Escondido moves towards indirect potable reuse

The City of Escondido in southern California, USA, could be about to follow neighbour San Diego in setting up an indirect potable water-reuse (IPR) scheme as part of a wastewater facility upgrade costing about US$ 200 million.

On 16 February 2011, the city council approved a request from utilities director Lori Vereker for a conceptual plan to address wastewater capacity and water reliability.

Faced with approaching capacity at the city’s Hale Avenue Resource Recovery Facility (HARRF), the city, which is 30 miles (48 km) north-east of San Diego, voted to use the plant’s upgrade to increase the use of recycled water for industrial/irrigation purposes and reduce ocean discharge. An agreement with Goal Line Energy (Iceoplex) is already close for recycled water use at the company’s energy production plant.

The city’s goal will be to work towards 100% reuse of wastewater from HARRF, with additional users likely to be parks, schools and the Wild Animal Park.

Referring to setting up IPR, Voreker’s report to the council said, “Our challenges include: no groundwater basins to recharge; small drinking-water reservoirs with limited retention time; and public perception about recycled water as a drinking-water source.”

The project might additionally generate revenue by using the existing outfall pipelines to the coast as regional brine lines.

The North County Times reported on 5 March 2011 that, anticipating the project, the Council approved a plan in February that would raise water rates by 12% in 2012, 8% in 2013, 7% in 2014 and 7% in 2015. In addition, the council agreed to increase sewer rates 6% per year in 2013, 2014 and 2015.

The city’s next step will be to implement recommendations from a reverse- osmosis/ultrafiltration pilot study which showed that more nutrient removal was required to meet the conditions for a wet-weather discharge permit and to proved a higher quality recycled water product. Vereker said the council’s approval of the conceptual plan was necessary because the city was about to spend “a large amount” on pilot studies and infrastructure costs.

She told the council that the alternative of upgrading the HARRF’s ocean outfall pipelines would cost around US$ 400 million and provide no positive benefit to the city. The utilities department estimates that at least 50% of the proposed spending can be recovered in grants.