Borrego Valley Groundwater Basin Borrego Springs Subbasin Draft - PowerPoint PPT Presentation

DRAFT WORK PRODUCT Borrego Valley Groundwater Basin Borrego Springs Subbasin Draft Fall 2017 Groundwater Monitoring Results Borrego Valley Groundwater Basin Sustainability Plan Advisory Committee Meeting January 25, 2018

2 Groundwater Elevation Monitoring Network Number of wells monitored : 36 Number of wells with transducers: 11 North Management Area: 6 wells Central Management Area: 16 wells South Management Area: 14 wells

3 North Management Area: Groundwater Elevation MW-1 420 Groundwater Elevation, in feet above 415 410 ID4-3 405 480 Groundwater Elevation, in feet above 400 460 NAVD 88 395 390 440 385 420 380 NAVD 88 Trend = -3 feet per year 375 400 370 380 2000 2005 2010 2015 2020 Trend = -2.52 feet per year 360 Date 1980 1985 1990 1995 2000 2005 2010 2015 2020 Date

4 Central Management Area: Groundwater Elevation ID4-1 Airport 2 480 500 Groundwater Elevation, in feet above Groundwater Elevation, in feet above 470 490 460 480 450 470 440 460 NAVD 88 430 NAVD 88 450 420 440 410 430 400 Trend = -1.85 feet per year 420 390 Trend = -1.17 feet per year 410 380 1980 1985 1990 1995 2000 2005 2010 2015 2020 400 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 2015 2020 Date Date ID1-16 450 Groundwater Elevation, in feet 440 430 above NAVD 88 420 410 400 390 Trend = -1.63 feet per year 380 1990 1995 2000 2005 2010 2015 2020 Date

5 South Management Area: Groundwater Elevation MW-3 480 MW-5A Trend = +1.34 feet per year Groundwater Elevation, in 418 475 Groundwater Elevation, in feet feet above NAVD 88 470 416 465 above NAVD 88 414 460 455 412 Trend = -7.15 feet per year 450 410 2001 2004 2006 2009 2012 2014 2017 2020 Trend = -0.65 feet per year 408 2005 2010 2015 2020 Date Date

6 Subbasin Groundwater Elevation Contour Map Working Draft – For Discussion Purposes Only

7 Groundwater Elevation Monitoring Network Number of wells monitored: 30 North Management Area: 6 wells Central Management Area: 9 wells South Management Area: 15 wells Monitored For: • Arsenic • Fluoride • Radionuclides (gross alpha particle activity) • Nitrate (as Nitrogen) • Sulfate • Total dissolved solids (TDS) General Minerals Cations • Calcium • Magnesium • Potassium • Sodium • Total hardness Anions • Bicarbonate • Carbonate • Chloride • Hydroxide • Total alkalinity

8 North Management Area: Arsenic Decrease from last sample Increase from last sample No change from last sample Decreasing trend Increasing trend NT No trend NT ND – Non-detect NS – No Sample Well Screen U – Upper Aquifer M – Middle Aquifer L – Lower Aquifer

9 Central Management Area: Arsenic Decrease from last sample Increase from last sample No change from last sample Decreasing trend Increasing trend NT No trend NT ND – Non-detect NT NT NS – No Sample Well Screen U – Upper Aquifer M – Middle Aquifer L – Lower Aquifer

10 South Management Area: Arsenic Decrease from last sample Increase from last sample No change from last sample Decreasing trend Increasing trend NT No trend ND – Non-detect NS – No Sample Well Screen U – Upper Aquifer M – Middle Aquifer L – Lower Aquifer

11 North Management Area: Nitrate Decrease from last sample Increase from last sample No change from last sample Decreasing trend Increasing trend NT No trend ND – Non-detect NS – No Sample Well Screen U – Upper Aquifer M – Middle Aquifer L – Lower Aquifer

12 Central Management Area: Nitrate Decrease from last sample Increase from last sample No change from last sample Decreasing trend Increasing trend NT NT No trend ND – Non-detect NS – No Sample NT Well Screen U – Upper Aquifer M – Middle Aquifer L – Lower Aquifer

13 South Management Area: Nitrate Decrease from last sample Increase from last sample No change from last sample Decreasing trend Increasing trend NT No trend NT NT ND – Non-detect NS – No Sample Well Screen U – Upper Aquifer M – Middle Aquifer L – Lower Aquifer

14 North Management Area: Sulfate Decrease from last sample Increase from last sample No change from last sample NT Decreasing trend Increasing trend NT No trend ND – Non-detect NS – No Sample Well Screen U – Upper Aquifer M – Middle Aquifer L – Lower Aquifer Sulfate MCL is the upper limit of the secondary MCL

15 Central Management Area: Sulfate Decrease from last sample Increase from last sample No change from last sample Decreasing trend Increasing trend NT NT No trend ND – Non-detect NT NS – No Sample NT Well Screen U – Upper Aquifer M – Middle Aquifer L – Lower Aquifer Sulfate MCL is the upper limit of the secondary MCL

16 South Management Area: Sulfate Decrease from last sample Increase from last sample No change from last sample Decreasing trend Increasing trend NT No trend ND – Non-detect NS – No Sample Well Screen U – Upper Aquifer M – Middle Aquifer L – Lower Aquifer Sulfate MCL is the upper limit of the secondary MCL

17 North Management Area: TDS Decrease from last sample Increase from last sample No change from last sample Decreasing trend NT Increasing trend No trend NT NT ND – Non-detect NS – No Sample Well Screen U – Upper Aquifer M – Middle Aquifer L – Lower Aquifer TDS MCL is the upper limit of the secondary MCL

18 Central Management Area: TDS Decrease from last sample Increase from last sample No change from NT last sample Decreasing trend Increasing trend NT NT NT No trend NT ND – Non-detect NT NS – No Sample Well Screen U – Upper Aquifer M – Middle Aquifer L – Lower Aquifer TDS MCL is the upper limit of the secondary MCL

19 South Management Area: TDS Decrease from last sample Increase from last sample No change from last sample Decreasing trend Increasing trend No trend NT ND – Non-detect NS – No Sample NT Well Screen U – Upper Aquifer M – Middle Aquifer L – Lower Aquifer TDS MCL is the upper limit of the secondary MCL

20 Radionuclides (Gross Alpha)

Questions and Discussion