SR0080641 SSNL - Laserfiche WebLink

Home Browse Search

Soil Suitability /Nitrate Loading Study Addendum Letter Nostra Vita Winery Lodi, California Irerracon May 20, 2019 revised June 10, 2019 Terracon Project No. NA197023 x 20 gpd) per event. The MCR Engineering civil plans dated June 2019 reported a higher flow rate for the 4,000 SF wine production building at 391 gpd; therefore, the MCR flow rate was used to calculate the maximum daily flow. The max daily flow rate for the facility is 3,441 gpd (650 gallons + 391 gallons + 2,400 gallons). Based on a review of the California Department of Water Resources, Groundwater Information Center Interactive Map, depth to groundwater is anticipated between 30 and 40 feet bgs. The groundwater flow direction and the depth to shallow, unconfined groundwater, if present, would likely vary depending upon seasonal variations in rainfall and other hydrogeological features. Without the benefit of on-site groundwater monitoring wells surveyed to a datum, groundwater depth and flow direction beneath the site cannot be directly ascertained. Based on a review of California State Water Resources Control Board GAMA website, there were no nitrate impacted wells identified on the site or surrounding properties. A domestic water supply well is located approximately 65 feet south of the existing wine tasting building. An agricultural supply is located near the southeastern corner of the site. A groundwater sample was not included as part of the SSNLS update. Refer to NOA SSNLS discussion above for information regarding the groundwater analysis in 2008. Based on a review of the boring logs contained in our Geotechnical Engineering Report for Nostra Vita Family Winery dated May 10, 2019 (Terracon Project No. NA195045), four borings B1 through B4 were advanced on the site to depths of 16.5 feet bgs. Based on a review of boring B2 site soils nearest the preliminary leach field consisted of fine to medium grained loose silty sand (0 to 4 feet), fine to medium grained hard silt with sand (4 to 6 feet), fine to medium grained dense silty sand (6 and 13 feet), fine to medium grained very stiff silt with sand (13 to 16.5 feet). Similar soils were encountered in the shallow percolation test borings. Groundwater was not encountered in the soil borings. Two shallow (3.5 feet bgs) percolation test borings(P2 and P3) were excavated in the preliminary leach field area at the northeastern corner of the site using a 4 inch diameter handauger. The borings were placed in the center of the preliminary leach field approximately 115 feet south of the domestic supply well. Boring P2 was excavated on May 15, 2019 and was found to be fully saturated on May 16, 2019 following an overnight rain event, therefore, an additional boring P3 was excavated on May 16, 2019 as a percolation test control. Approximately two inches of "pea gravel' was placed in the bottom of the open borings. A 2.0-inch diameter PVC pipe with perforations towards the bottom was installed on top of the gravel and the annular space was backfilled with "pea gravel". Presaturation of boring P3 occurred approximately 24 hours prior to the day of testing. Approximately 1.0 foot of clear water was added above the top of the gravel. Boring P2 was fully saturated with approximately 3.0 feet of water above the top of gravel due to the overnight rain event, therefore no water was added. Both borings were found to be dry and intact after the 24-hour pre-soak period. Responsive ■ Resourceful ■ Reliable 5