Many wineries are interested in recycling wastewater for irrigation. This project investigates the effects on winemaking when winery wastewater (WW) is recycled for irrigation. Water samples and soils samples were collected from one Napa Valley and one Sonoma vineyard. Leaf and berry samples were collected at veraison (mid-season) and at harvest, with harvested grapes being made into wine for a sensory trial. All samples were analyzed for Na, Mg, K, and Ca metals by inductively coupled plasma mass spectrometry (ICP-MS), and the grape and wine samples were also analyzed for total phenolics and tannins. The presence of grape compounds and detergents caused the WW concentrations of K to be 143x higher than the control irrigation water. The soil samples showed significant accumulations of Na and K between treatments while the leaf samples showed significant differences in Na, Mg, K, and Ca between treatments, but the majority of these were slight. The grape samples showed significant differences in Na and Ca concentrations while the wine showed minor but significant differences in all metal concentrations. The sensory study on the Napa vineyard showed no statistical significance between the finished wines.

Funding Support: Agricultural & Natural Resource Competitive Grants