Carlsbad, Calif. — The Encina Wastewater Authority plant here claims to be one of the greener – if not the greenest – treatment facility in the country. Virtually nothing goes out the other end that can’t be reused. That includes recently collaborating with Ostara Nutrient Recovery Technology to remove phosphorus buildup in piping and machinery that reduces plant efficiency and increases maintenance cost. “Ostara, which will market the phosphorus as fertilizer, will mine out our discharge water from the centrifuges,” explained Eric Have, Encina biosolids sales and marketing manager. “It doesn’t affect our system taking the discharge water through the plant again. Just another way of utilizing everything that comes into our plant and helping us to run at about 96 or 97 percent efficiency. We don’t have anything left over.” In addition, as of Feb. 1 Encina has started switching over from providing a cement plant biosolids for incinerating to producing higher-value biosolids fertilizer for golf courses and other users. Have said that 6,500 tons per year of 5.7-7-0 Class A EQ (exceptional quality) biosolids are being produced and shipped all over the United States. “We have customers who want our PureGreen in Arkansas but haven’t gotten to them as yet,” Have reported. At the same time, Encina provides 3.5 million gallons of recycled water every day to the city of Carlsbad. General Manager Kevin Hardy noted that the technology is part of a growing trend of wastewater treatment facilities finding value in biosolids as “wastewater facilities are starting to see their purpose can go beyond treating wastewater, realizing that environmental benefits that are profitable can be extracted onsite.” Encina, which serves more than 350,000 North County residents, is owned by six public agencies under a joint powers agreement to share in the costs and management to get more economical and high-tech facilities than they could on their own.
Transparency Across the Fertilizer Value-Chain