Encina Wastewater Authority | 637 followers on LinkedIn. Protecting public and environmental health for generations to come. | The Encina Wastewater Authority (Encina) is a public joint powers authority located in North San Diego County. Founded in 1961, Encina provides regulated and wastewater treatment services to approximately 380,000 residents and industrial users in a 123-square mile service area. Encina accomplishes this through the operation, maintenance, and administration of the Encina Water Pollution Control Facility (EWPCF) on behalf of its six (6) Member Agencies: The City of Carlsbad, The City of Vista, Buena Sanitation District, Vallecitos Water District, The City of Encinitas, and Leucadia Wastewater District.