Over the past several years, regulatory requirements have significantly increased for water providers. Among these requirements are Federally mandated wellhead protection programs. Administered and enforced by State agencies, each purveyor may voluntarily prepare and submit a wellhead protection plan. The plan must include a designated protection area for each water source based on site specific hydrogeologic conditions, and establish policies by which the protection program must be implemented. Methods of wellhead protection include land ownership of areas around the water source, community zoning for land around the area, and leasing or fencing of an area that could impact the well to assure continued protection of the source from potential sources of contamination.

Wellhead protection areas (WHPAs) can be determined by a number of methods. Generally, WHPA delineation is based on establishment and understanding the interactions of distance, drawdown, time of travel, and hydrogeologic flow boundaries. Physical processes such as advection, hydrodynamic dispersion, and solid-solute interaction also play a part in delineation of WHPAs. Distance is commonly the first step towards delineation, and is particularly effective for microbial protection zones and establishing setbacks for pesticide applications.

Other criteria for WHPA delineation include distance drawdown evaluations for active wells, identification of capture zones, and definition of particle time of travel distances. If sufficient aquifer hydraulic data are available, a computer model of the well head area can be used to establish the WHPA. This is commonly the most efficient and inexpensive method, given correct information is available.

As water supplies begin to manifest impacts from development and continued depletion, particularly in the western United States, many water planning agencies have turned to Aquifer Storage and Recovery (ASR) to store surplus supplies, and serve as a reservoir for later extraction. ASR technology is relatively new, with most major developments taking place in the last decade. Common techniques for ASR include use of rapid infiltration basins to collect and infiltrate stormwater runoff; dams along stream, river, and creek beds to capture stormwater and flow events for infiltration; construction of storage dams and reservoirs with diversion of surface water for recharge; and the use of artificial recharge wells for direct injection of potable water.

Converse has been involved with numerous projects using a variety of exploration and testing methods to evaluate potential recharge sites. Using ASTM and EPA methods for infiltration testing, Converse has successfully sited numerous infiltration sites. In addition, our extensive background in drilling, lithologic logging, and hydrogeology has been utilized for design and installation of artificial recharge wells, and screening for large surface water reservoirs to serve as multipurpose facilities that include ASR.

Converse deploys proven field investigation techniques and computer analysis to evaluate subsurface conditions in order to provide effective recommendations to the Contractor and Developer for mitigation of the many risks involved with construction below the water table.