The town of Yountville’s Recycled Water Program was submitted in 2015 for the Public Works, Infrastructure, and Transportation award category.
Home to 2,900 residents in the Napa Valley, Yountville decided to expand its recycled water program in response to the challenge of using water in an environmentally sustainable way while supporting the needs of the local agriculture and economy.
An 18-hole golf course located 5 miles southeast of town became Yountville’s first recycled water customer. Later converted to vineyards and continues, the land continues to use the recycled water to irrigate. As the popular wine region expanded, two additional wineries started using recycled water. A nine-hole golf course was built on the property adjacent to the Yountville Wastewater Treatment Facility. With this new development, approximately 45-50 percent of the entire amount of wastewater treated at the facility was being utilized between three vineyards and the new golf course for irrigation purposes.
The complex regulatory environment also posed a challenge to Yountville’s water efforts. In 2005 the town negotiated with the San Francisco Bay Regional Water Quality Control Board to renew the National Pollutant Discharge Elimination System Permit for the Wastewater Treatment Facility. This would require the town to install expensive equipment in the Napa River that would be difficult and invasive to native species to construct and maintain. Instead, it was later agreed that in lieu of this proposal, the town would expand its already successful Recycled Water Program. This solution would set the stage for a new way of thinking about water and how to use it in a way that made sound fiscal and environmental sense. This process made it possible to save water in the underground aquafers for domestic future use.
An unusually dry winter in early 2009 precluded Yountville from discharging its treated wastewater to the Napa River because there was not adequate dilution due to the lack of flow in the river. This became an opportunity to increase public-private partnerships and allowed Yountville to negotiate a short term agreement with a vineyard in close proximity to the existing recycled distribution pipeline. The relationship more than doubled the existing volume of storage previously available. Yountville was now able to recycle 87 percent of wastewater due to the fact that the ponds on the new property were completely empty and it was an extremely dry winter.
The solution to providing a sustainable use of recycled water involved partnerships that promoted community engagement, applications of new technology and improved services. Yountville sought advice in how best to remedy and avoid the constraints within the Wastewater Treatment Facility and to allow for the production of Title 22 Unrestricted Level Recycled Water, which has specific standards for recycled water. The scope of the project included the demolition of existing equipment/facilities that were no longer in service, construction of a new larger Chlorine Contact Chamber, Effluent Holding Pond Bypass Structure (allowing treated recycled water to be pumped directly to customers without having to first pass through the storage pond), and the installation of new coagulant storage and pumping facilities to increase solids capture and filter upgrades.
The first phase of the Title 22 construction project enabled customers to utilize the upgraded level of treated recycled water for expanded purposes such as indoor plumbing of toilets and other non-potable uses and increased fire protection (fire sprinklers). Additionally, this higher level of treated recycled water could now be used for what is known as heat protection during unusually hot periods. Recycled water could now be distributed through overhead sprinklers and could come in contact with the edible portion of the fruit. The Title 22 Upgrade Project was completed in 2010 and now meets several of the requirements set forth by the Regional Water Quality Control Board.
The first phase’s success led to phase two, the Recycled Water Expansion Project. Funded through the State Revolving Fund , Yountville worked with consultants to design the elements of the expansion. This included the installation of approximately 4,500 linear feet of 8 inch purple PVC pipe to connect a fifth vineyard customer to the recycled water distribution system, Supervisory Control And Data Acquisition functionality to allow remote operation and monitoring of the entire recycled water distribution system and several portions of the Wastewater Reclamation Facility, new larger recycled water pumps, and new filter media installation and other minor treatment plant modifications.
In 2011, the amount of wastewater used for irrigation purposes was approximately 55 percent. This number has increased by nearly 10 percent each year to allow the town of Yountville to beneficially reuse 83 percent of its wastewater in 2014. With the addition of a fifth vineyard customer, Yountville will be able to recycle 100 percent of the wastewater generated by the town during periods of extreme drought. From an environmental perspective, the numbers speak for themselves — using recycled water for irrigation reduces the need for potable water.
Yountville continues strong public outreach both at the local and regional level to help other agencies learn from the success of the recycled water program.