APPENDIX J CRYSTAL GEYSER ONSITE IRRIGATION SYSTEM TECHNICAL MEMORANDUM

Transcription

1 APPENDIX J CRYSTAL GEYSER ONSITE IRRIGATION SYSTEM TECHNICAL MEMORANDUM

2 DRAFT TECHNICAL MEMORANDUM Crystal Geyser Onsite Irrigation System PREPARED FOR: PREPARED BY: REVIEWED BY: Richard Weklych/CGWC Barbara Brenner/Churchwell White Kerilyn Paris/CH2M Peter Rude/CH2M DATE: August 18, 2016 PROJECT NUMBER: This technical memorandum provides details for Alternative 4 proposed in the Crystal Geyser Mt. Shasta Facility Wastewater Discharge Alternatives technical memorandum. The onsite irrigation system is discussed below and may be further evaluated in the Environmental Impact Report (EIR). Background Information and Assumptions The Crystal Geyser Water Company (CGWC) Mt. Shasta Facility is located on 210 Ski Village Drive in Mt. Shasta, CA. The facility includes several acres of CGWC property available for land application of treated process wastewater. Alternative 4 involves treating the industrial wastewater onsite, and discharging it to either the onsite leach field or onsite irrigation locations as shown on Figure 1. The land application will occur during the irrigation season from May through October. It is assumed that plant operations will use one bottling line during Phase 1. In Phase 2, two bottling lines will be operational. In Phase 1, the treated process wastewater can meet the irrigation requirements of approximately 6.5 acres of trees. In Phase 2, 12 acres of trees can be irrigated. Soil Conditions A custom soil resource report was downloaded from the United States Department of Agriculture (USDA) Natural Resources Conservation Service (NRCS) for the planned irrigation area. The soil is Deetz gravelly loamy sand, with 0 to 5 percent slopes. The depth to a restrictive feature is more than 80 inches and the natural drainage class is somewhat excessively drained. The hydraulic capacity of the soil is high to very high and the depth to the water table is more than 80 inches. Assumptions The tree crop is assumed to be irrigated from May through October. For the irrigation system design, plant operations are assumed to be 24 hours per day, Monday through Friday, therefore 22 days per month, on average. No irrigation is assumed to occur during any weekend operations. In Phase 1, one bottling line will produce 54,000 gallons per day of treated wastewater, a maximum flow rate of 37.5 gallons per minute (gpm) from the treatment plant. Phase 2 with two bottling lines will produce approximately 100,000 gallons per day, and a flow of 75 gpm from the treatment plant. To be conservative, an assumed flow rate of 30 gpm was used for the selection of the storage tank size. 1

3 CGWC Bottling Facility Aerial photo source: Google 2016, modified by CH2M HILL. LEGEND Dry Creekbed Exposed Rocks Eastern Field Northern Field Eastern Irrigated Area Northern Irrigated Area WT RDD Figure1_PotentialOffsiteIrrigation_V2.ai cmont 08/17/16 0 North 300 Approximate scale in feet 600 Figure 1 Potential Onsite Irrigation Locations Crystal Geyser Water Company Mt. Shasta, CA

4 Design Process CRYSTAL GEYSER ONSITE IRRIGATION SYSTEM The goal of the design is to meet crop evapotranspiration (ETc) of the crop with the land application of treated wastewater from the plant. The land application acreage of 9 and 3 acres was determined by balancing the demands of the crops with the outflow of the plant. In selecting the layout of the irrigation sets, the 50-foot buffer area for land application is included. Figure 1 shows the areas to be irrigated, along with the 50-foot buffer zones. The Eastern Field is approximately 9 acres and the Northern Field is approximately 3 acres. The ETc was obtained from the ITRC California Evapotranspiration Data for sprinkler irrigation for a typical year (ITRC, 2016). For irrigation design purposes, the crop to be grown was assumed to be similar to Christmas trees. Therefore, a peak ETc of 6.3 inches (in July) for Christmas trees is used for this design. Due to the height of the sprinklers (4 to 6-ft above ground), the spray losses are estimated to be 12- percent and the irrigation distribution uniformity of 75-percent, resulting in a 66-percent irrigation efficiency. The gross application rate determined using the irrigation efficiency is approximately 9.5 inches for the peak month of July. To meet this irrigation requirement, a flow rate of 98 gpm per acre is needed. Using the gross application rate and the maximum spacing recommendations listed above, the sprinklers and sprinkler spacing were selected. The maximum recommended spacing is 40% of the sprinkler diameter between sprinklers, and 65% of the sprinkler diameter between lateral pipes, for wind speeds less than 7 miles per hour (Burt, 2013). The average wind speed for a typical year (1997) from May through October is 3 miles per hour in Mt. Shasta, CA, therefore the maximum recommended spacing was used (Wunderground, 2016). The spacing is 30 feet down the lateral and 45 feet between laterals for both fields, for a 78-foot sprinkler diameter. From the sprinkler sizing and spacing, the pressure loss was calculated and then the pumps were sized. The following section presents the preliminary design selections. Phase 1 Preliminary Design Layout For Phase 1, only the Eastern Field will be irrigated in four sets for two hours per set per day, for a total of 22 days per month. This results in a total daily irrigation time of 8 hours each irrigation day. The Phase 1 system will use up to 80,000 gallons per day. To compensate for fluctuations in outflow and allow for adequate flow to the sprinklers, a 100,000 gallon storage tank will be used. This storage tank will also accommodate the additional flow in Phase 2. One inline pump will supply the field with pressurized water, with a standby pump for backup. Figure 2 shows the approximate mainline locations for Phase 1. Phase 2 Preliminary Design Layout In Phase 2, both the Eastern and Northern Fields will be irrigated with up to 108,000 gallons per day. The fields can use up to 120,000 gallons to meet the ETc of the trees. On the Eastern Field, irrigation will remain the same for Phase 2 as in Phase 1. For the Northern Field, two sets will be irrigated for two hours each, also for a total of 22 days per month. Total irrigation time for the two fields will be 12 hours each day. The storage tank from Phase 1 will be adequate for the additional flows. Two separate inline pumps will be used to supply each of the fields. For redundancy, a standby pump will be provided for each of the duty pumps. Figure 3 shows the approximate mainline locations for Phase 2. 3

5 CGWC Bottling Facility Flow from Storage Tank Aerial photo source: Google 2016, modified by CH2M HILL. LEGEND Mainline Eastern Field Eastern Irrigated Area 0 North 150 Approximate scale in feet WT RDD Figure2_Phase1ApproxMainlineLayout_V2.ai cmont 08/17/ Figure 2 Phase 1 Approximate Mainline Layout for Onsite Irrigation Crystal Geyser Water Company Mt. Shasta, CA

6 CGWC Bottling Facility Flow from Storage Tank Aerial photo source: Google 2016, modified by CH2M HILL. LEGEND 0 Mainline Eastern Irrigated Area Eastern Field Exposed Rocks Eastern Irrigated Area Northern Field WT RDD Figure3_Phase2ApproxMainlineLayout_V2.ai cmont 08/17/16 North 300 Approximate scale in feet Northern Irrigated Area 600 Figure 3 Phase 2 Approximate Mainline Layout for Onsite Irrigation Crystal Geyser Water Company Mt. Shasta, CA

7 CRYSTAL GEYSER ONSITE IRRIGATION SYSTEM References Irrigation Training and Research Center (ITRC) California Polytechnic State University, San Luis Obispo ETc Table for Irrigation Scheduling and Design, Zone 10 Monthly Evapotranspiration, Sprinkler Irrigation Typical Year. Date accessed: 27 July Website: United States Department of Agriculture (USDA) Natural Resources Conservation Service (NRCS) Custom Soil Resource Report for Siskiyou County California, Central Part. Date accessed: 27 July Website: Burt, C Irrigation Design Manual. Irrigation and Training Research Center, California Polytechnic State University. 6

8 Appendix A Custom Soil Resource Report, Soil Description

9 Custom Soil Resource Report Siskiyou County, California, Central Part 125 Deetz gravelly loamy sand, 0 to 5 percent slopes Map Unit Setting National map unit symbol: hdnk Elevation: 3,000 to 5,000 feet Mean annual precipitation: 30 to 45 inches Mean annual air temperature: 46 to 48 degrees F Frost-free period: 125 days Farmland classification: Not prime farmland Map Unit Composition Deetz and similar soils: 85 percent Minor components: 15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Deetz Setting Landform: Outwash fans Landform position (two-dimensional): Summit Landform position (three-dimensional): Tread Down-slope shape: Linear Across-slope shape: Linear Parent material: Glaciofluvial deposits derived from igneous rock Typical profile H1-0 to 7 inches: gravelly loamy sand H2-7 to 38 inches: stratified sand to gravelly loamy sand H3-38 to 65 inches: stratified very gravelly sand to gravelly loamy sand Properties and qualities Slope: 0 to 5 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Somewhat excessively drained Runoff class: Negligible Capacity of the most limiting layer to transmit water (Ksat): High to very high (5.95 to in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Available water storage in profile: Very low (about 2.9 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 4s Hydrologic Soil Group: A Minor Components Rock outcrop Percent of map unit: 5 percent Riverwash Percent of map unit: 5 percent 12

10 Custom Soil Resource Report Landform: Drainageways Xerofluvents Percent of map unit: 5 percent Landform: Flood plains 13