San Benito County Water District San Benito County Water District

Table D-3. Percolation of Municipal Wastewater during Water Year 2008
Effluent
Pond Area Discharge Evaporation Percolation
(acres) (acre-feet) (acre-feet) (acre-feet)
Hollister -- domestic 92.9 1,927 347 1,580
Hollister -- industrial 39.0 1,403 146 1,257
Ridgemark Estates I & II 7.2 156 17 139
Tres Pinos 1.8 26 7 19
Total 140 3,486 510 2,977
Notes:
n.a. = not applicable. Average annual evaporation = 56 inches (DWR Bulletin 73-79)
Assumes 80% of total pond area in use at any time (Rose, pers. comm.). Hollister pond areas are from Dickson and Kenneth D. Schmidt and Associates (1999) and include
treatment ponds in addition to percolation ponds at the domestic wastewater treatment plant.
The San Juan Bautista plant is not included because the unnamed tributary of San Juan Creek that receives its effluent usually gains flow along the affected reach and is on the
southwest side of the San Andreas Fault. These conditions prevent the effluent from recharging the San Juan Subbasin.
Flow data are accurate to a maximum of two significant digits. All digits are shown to avoid rounding small numbers to zero and to preserve correct column totals.
D-3 Percolation of Wastewater
Todd Engineers 11/26/2008