Page 21 - Yucaipa Sustainable Groundwater Management Agency - Yucaipa SGMA

rates for a full‐scale recharge basin to support the Yucaipa Basin GSP process. Knowledge
gaps and recommendations for additional investigation work at favorable recharge sites are
also presented to support the design of new recharge facilities and rehabilitation of existing
recharge/storm detention basins.

1.1. SCOPE OF WORK

The scope of work for the investigation included the following activities:

1. Attendance at a pre‐construction meeting (held on May 15, 2018) to confirm site
access for heavy machinery; delineate test basin excavation limits and dimensions;
confirm preferred water source, pressure, and anticipated delivery rates; and review
procedures for test basin construction, soils management requirements,
conveyance and instrument setup, and site security fencing and traffic control.

2. Refinement of detailed site‐specific work plans to accommodate physical constraints
prior to field mobilization, and determination of the optimal test sequence based on
site prioritization and intra‐site proximity to consolidate equipment requirements
and minimize rental costs.

3. Fabrication of two flow control systems/skids and associated valves and switches for
automated flow and water level control and alert functions.

4. Implementation of twelve infiltration tests at eleven sites (conducted over a twelve‐
week period from July 9 to October 1, 2018). Activities included (a) mobilization and
demobilization of equipment and heavy machinery, (b) excavation and backfill of an
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approximately 1,000‐square foot (ft ) by 5‐foot deep test basin, and (c) installation
of test equipment, site monitoring components, security fencing, and traffic ramps
and signage to ensure reliable collection of field data and public safety.

5. Routine site visits to document flow rates/volumes and non‐routine site visits to
troubleshoot/address equipment issues and modify the test approach to maximize
the value of collected data.

6. Project Management. Todd Groundwater subcontracted Drewelow Remediation
Equipment Inc. (DRE) (Escondido, California) to fabricate the flow control
systems/skids and implement the field infiltration testing. Todd Groundwater
provided overall project management, field supervision, and schedule coordination
for the project.

1.2. PREVIOUS INVESTIGATIONS

Over the past several years, Valley District and its partner agencies have been proactive in
building the technical foundation for developing a groundwater recharge program in the
Yucaipa Basin. Recent studies and investigations have improved the understanding of local

Infiltration Testing at Eleven
Investigation Sites in the Yucaipa
Basin, Yucaipa Valley, CA 2 TODD GROUNDWATER

Yucaipa Sustainable Groundwater Management Agency - January 23, 2019 - Page 21 of 137