California Water Science Center (CAWSC) - San Diego Hydrogeology Project (SDH)

Site Description for Sweetwater (17S/2W-28R4-9)

Station No.: 323932117050801-5 017S002W28R004-9S   Agency: USGS

LOCATION.--Lat 32°39'32.53", Long 117°05'08.08" referenced to North American Datum of 1983, in NW 1/4 SW 1/4 SW 1/4 sec.28, T.17 S., R.2 W., San Diego County, CA, Hydrologic Unit is 1807030410.

DATUM.--Land-surface datum is 70.85 ft above North American Vertical Datum of 1988. Measuring point: MEASURINGPOINT.

EQUIPMENT.--Instrumentation consists of a Design Analysis H350XL data logger transmitting through a Design Analysis SE-300 GOES HDR transmitter (DCP), five Insitu model Level Troll 500 non-vented pressure transducers, and one Insitu model Baro Troll 500 barometer. A rechargeable 12-volt battery and solar panel provides power. Instruments are housed in a subterranean concrete and steel vault (with a USGS 2640 lock). Water levels are obtained using a calibrated electrical tape and calibrated pressure gage.

HYDROLOGIC CONDITIONS.--The USGS well site is located within 500 ft of three Reynolds Desalination Facility production wells (SDF6, SDF1, SDF2). Water levels in all six observation wells may be affected by pumping and injection. USGS observation wells #1 and #2 (deepest wells) are least affected. USGS well #3 is in a fine-grained unit and may respond to pumping and injection. USGS well #4 is perforated in a production zone. USGS wells #5 and #6 are affected by surface water (estuary). Well #1 is artesian.

WATER LEVEL RECORD.--Real-time continuous monitoring since December 2009, in cooperation with Sweetwater Water Authority. Water-level data collected at 15-minute intervals and reported as "Depth Below LSD" and "Water level, NAVD".

GAGE.--Instrumentation consists of a Design Analysis H500XL data logger transmitting through a Design Analysis SE-300 GOES HDR transmitter (DCP), six Insitu model Level Troll 500 non-vented pressure transducers, and one Insitu model Baro Troll 500 barometer. A rechargeable 12-volt battery and solar panel provides power. Instruments are housed in a subterranean concrete and steel vault.

WELL CHARACTERISTICS.--The USGS well site is located within 500 ft of three Reynolds Desalination Facility production wells (SDF6, SDF1, SDF2). Water levels in all six observation wells may be affected by pumping and injection. USGS observation wells #1 and #2 (deepest wells) are least affected. USGS well #3 is in a fine-grained unit and may respond to pumping and injection. USGS well #4 is perforated in a production zone. USGS wells #5 and #6 are affected by surface water (estuary). Well #1 is artesian.

TOPOGRAPHIC MAP: National City, scale 1:24000

COOPERATION: Sweetwater Authority

ROAD LOG: Key intersection is the intersection of Interstate Highway 5 and Highway Route 94 about near downtown San Diego. Directions are given from Interstate Highway 5 south towards National City.