In 1997, the San Antonio Water System (SAWS) began a study to determine the feasibility
of developing an aquifer storage recovery (ASR) facility to provide potable water to meet peak
seasonal demands and reduce peak withdrawal rates from the Edwards aquifer. The test drilling
program suggested that the Carrizo aquifer was suitable for storage of several potential source waters.
Also, during the second part of the feasibility investigation, it was determined that the Carrizo aquifer
in South Bexar County could provide a substantial supply of new-source groundwater for many years.
Therefore, SAWS determined that the development of a conjunctive use project, incorporating an
ASR element and a groundwater production element, would be in the interest of San Antonio. This
approach provides the most rapid development of the supply source. During the first phase, the ASR
system was developed to provide a groundwater supply of 30 million gallons per day (mgd). A total
of 17 wells were constructed to supply raw groundwater to a new water treatment plant, pumping
station, and transmission pipeline. A bypass around the pumping station and the water treatment plant
was constructed to facilitate recharge. Phase 1 is currently operational.
Water from these facilities is transported into San Antonio to two terminal points where it is delivered
into the SAWS distribution system. Currently, these points are the Seale Pump Station and at the
Artesia Pump Station. Additional terminal points are currently under construction for Phase 2.
Phase 2 of the ASR Program originally anticipated expansion of the system to 60 mgd of recovery
capacity. All Phase 1 facilities were designed to operate at a minimum 60-mgd rate. Planned
enhancements necessary to achieve the 60-mgd capacity included construction of up to 17 new ASR
wells and the installation of one 20-mgd high service pump at the water treatment plant high service
pump station (HSPS).
The Carrizo ASR System Capacity Analysis was conducted to define the approximate system
capacity for both Phase 1 and Phase 2 conditions, over various operating periods. The system
component that limits capacity for each operating period is identified. Results of the Phase 1 analysis
provide an estimate of as-built system capacity. The Phase 2 analysis was useful in planning the
build-out configuration of the South Bexar County site and in establishing an appropriate design
capacity for the Phase 2 expansion.
As part of the analysis, the aquifer recharge and recovery capacity for the South Bexar County site
currently under SAWS ownership was estimated. The analysis was conducted to provide a planning-level estimate of the ultimate site capacity. A one-year recovery cycle for the Carrizo aquifer was
selected for the analysis. Includes reference, tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 510 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 14 |
| Published : | 09/01/2006 |
