Evaluation of Groundwater Supply Alternatives Within Bernal Subbasin

Testing, Sampling, and Analysis Plan January 15, 2025 1 Zone 7 Water Agency and City of Pleasanton 1. INTRODUCTION AND PURPOSE This Testing, Sampling, and Analysis Plan (plan) was prepared to satisfy Task 2 of the scope of work described in the Regional Groundwater Facilities Project Feasibility Study (Scope) for the Zone 7 Water Agency (Zone 7) and the City of Pleasanton (City), dated September 17, 2024. This Plan details the procedures, methods, timelines, analytes, test methods, sample control, chain of custody forms and documentation, and turnaround times for the sampling that will be completed on the newly constructed test wells that will be constructed under Task 1 of the Scope. Each well will be pump tested to assess well performance, subject to spinner analysis to characterize zonal flow within the well, and collection of zonal and composite water samples for analysis. Groundwater sampling activities will include Title 22 drinking water analysis as described in the California Code of Regulations (CCRs). Constituents, laboratory analytical methods, and practical quantitation limits are summarized in Attachments 1 and 2. The purpose of this Plan is to provide guidance to qualified professional personnel engaging in the collection of well performance data and analysis of groundwater quality data. Use of this Plan intends to promote the collection of high-quality data, thereby supporting data usability. Testing and sampling procedures and protocols outlined herein are in accordance with pertinent current Environmental Protection Agency (EPA) Standard Methods, California Code of Regulations Title 22, and current industry standards and practices. 2. WELL AND AQUIFER TESTING After final development and when the well meets the specified performance requirements, tests will be performed. The first test will be an 8-hour step pumping test to determine the target design capacity of the well. The second test will be an 8-hour constant rate pumping test at the final design capacity as determined by the Engineer based upon evaluation of well performance during the step test. The test capacities will be determined by the Engineer before or during the testing based upon the results of development and test pumping. Well and aquifer testing shall not exceed 20 hours without written direction from the Engineer/Owner. 2.1. Well and Aquifer Testing Procedures A. Static Water Level a. At the start of each day of pumping, the Contractor shall record the static water level in the well (see Section 5.1). At all other times, the static water level shall be considered to be attained when three successive water level measurements spaced ten minutes apart show no appreciable change. B. Flow Metering a. During each test or step, the discharge of the pump shall be measured with an accurate, calibrated totalizing and instantaneous flow meter, or other type as approved by the Engineer. The pump discharge rate shall be maintained at all times during the test within