Groundwater recharge with recycled wastewater is viewed as a necessity in
water-short areas. In California, the coastal overdraft situation is already
alarming and threatens to become worse. The purpose of groundwater recharge with
recycled wastewater is to stop declining levels of groundwater, protect the
coastal aquifers against saline intrusions, provide inexpensive storage and
transmission of the recharged water, ameliorate problems of land subsidence, and
provide additional treatment of the recycled water. This paper presents the case
study of West Coast Basin, which provides about 20% of the potable water supply
in the West Basin Municipal Water District (WBMWD) service area. In order to halt
further seawater intrusion, the West Coast Basin Barrier Project (WCBBP) was
initiated by the Los Angeles County Department of Public Works (LADPW) and
involves the injection of potable water in order to maintain groundwater levels
high enough to prevent further seawater intrusion. In mid- 1995, WBMWD began
producing recycled wastewater, which is currently blended with potable water
prior to injection. The main goal of a new R&D program, started in 1998, is to
provide a technical and scientific basis to better understand the transport of
recycled wastewater within the West Coast Basin. An important regulatory issue
for approving the operation of indirect potable reuse projects, is the tracing
and modeling of the behavior of recycled wastewater in the aquifers. Simulations
using a groundwater flow, solute transport and salt water intrusion models in the
West Coast Basin were carried out in 1993 to address regulatory requirements
relating to injection of recycled wastewater into the WCBBP. Earlier model
simulations evaluated the effectiveness of the barrier in preserving the aquifers
from saline intrusion and in controlling the advancement of inland saline plumes.
This paper presents the first results of the application of a new hydrodynamic
and hydrodispersive geographic information system (GIS) model, taking into
account the differences in density of salt water and the use of boron isotopes
for recycled wastewater tracing purposes. Includes 6 references, tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 1.7 MB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 15 |
| Published : | 01/01/2000 |
