CA water district's treated wastewater solids offer sustainable fertilizer alternative

The Vallecitos Water District advocates organic biosolid pellets as a less harmful and environmentally friendly alternative to chemical fertilizers.

SAN MARCOS, CA, May 22, 2013 --The Vallecitos Water District (Vallecitos) is incorporating organic biosolid pellets, composed of treated wastewater solids, into its Sustainable Demonstration Garden located in front of its San Marcos Administrative offices, instead of using chemical fertilizers.

The pellets are rich in nutrients, such as nitrogen and phosphorus, and makes them ideal as a valuable fertilizer. They also offer a less-harmful alternative to the typical chemical fertilizer that can pollute the ocean after being washed off during rain or over-irrigation. Instead, the pellets are made of organic material, requiring infrequent application because they break down slowly to nurture the garden and provide nutrients to plants as needed.

The plant-nourishing pellets are created at the Encina Wastewater Authority's (Encina) treatment facility in Carlsbad. Solids that are removed during the wastewater treatment process are heat dried to about 200 degrees Fahrenheit to kill pathogens and remove excess water to create the dry, biosolid pellets. Vallecitos is one of six public agencies that own the Encina facility.

The dispersing of the pellets is just another sustainable aspect to the garden that already features decorative water features that run on collected rain water and solar power, synthetic turf, micro-irrigation, mulch, rockscapes, California native plants, and weather-based irrigation controller displays to promote the value of preserving natural resources today for availability tomorrow.

To date the majority of the biosolid pellets have been purchased in large quantities by a cement manufacturer that incinerates the pellets in place of coal. In the energy-intensive cement manufacturing process, biosolid pelllets provide an alternative renewable energy source to fossil fuels. Encina is also selling the product in bulk to local golf courses, nurseries, and fertilizer blending companies. The pellets are currently not available to the public, although it is a long-term goal to distribute them in smaller quantities so that they can be used in the local service area.

A sample of the biosolid pellets is available to view at the Vallecitos Water District Administration building located at 201 Vallecitos de Oro in San Marcos. Visitors are welcome to the garden anytime during business hours from 8 a.m. to 5 p.m., Monday through Friday.


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