Our water supply team of water resource engineers, hydrogeologists, water well contractors, and environmental scientists is committed to developing sustainable water supplies. We routinely perform hydrogeologic investigations, aquifer performance tests, water quality studies, wellfield design, water supply planning, groundwater modeling and consumptive water use permitting. In addition, we permit deep injection wells, perform mechanical integrity tests, geophysical logging, and obtain Public Services Commission certification of new water utilities.
Town & County Utility Company
Johnson Engineering performed a hydrogeologic investigation of the Upper Floridan Aquifer System, including design, testing, fulltime construction observation and administration of two test production wells and two dual-zone monitor wells at two test sites. Testing of these wells included full suite geophysical logging, packer testing and aquifer performance testing to assess water quality changes within the aquifer both vertically and laterally. The APT data were used to develop a conceptual layout and design, and groundwater flow model for a 7 MGD PWS wellfield. The drilling program took place concurrently with water use permitting in order to expedite the process. Data collected from this investigation also supported DRI and comprehensive plan amendment applications. Johnson Engineering also assisted in the original PSC certification of the utility.
Lee County Utilities-Corkscrew Wellfield Expansion
Johnson Engineering was responsible for the design and permitting of a 5 MGD expansion of the Corkscrew Wellfield for Lee County Utilities. Johnson Engineering performed initial hydrogeological investigations of the Floridan and Sandstone aquifers at the site, including test well construction, water quality sampling and aquifer performance testing. Based on the results of groundwater flow and transport modeling using data obtained from the testing program, Johnson Engineering produced a final wellfield design incorporating 24 production wells in three aquifer systems and 35,000 feet of raw water transmission line. The wellfield expansion and reconfiguration greatly enhanced supply while reducing impacts to natural systems in the area.
Lee County Utilities-SFWMD Water Use Permit Renewal
Johnson Engineering is assisting Lee County Utilities in renewal and modification of a 40 MGD water use permit covering two major wellfields and Caloosahatchee River withdrawals. As part of this effort, Johnson Engineering has performed extensive analyses of historical water level, rainfall and pumpage data, changes in watershed boundaries and land uses from 1944 to 2008, along with groundwater modeling, and mitigation and wellfield operation plan preparation. Data analysis has shown that the revised wellfield configuration, originally designed and permitted by Johnson Engineering in 2003, has been effective in reducing drawdown in the Surficial aquifer, even throughout a prolonged drought, and has allowed water levels to recover to nearly pre-development conditions.
North Fort Myers Utility Deep Injection Wells
Johnson Engineering performed the recent operation permit renewal and mechanical integrity testing of North Fort Myers Utility’s deep injection well, which included casing pressure tests, and high resolution temperature, video and radioactive tracer surveys. As part of the operation permit renewal, issues related to the existing dual-zone monitor well were identified. Johnson Engineering was responsible for the construction administration for rehabilitation of the dual-zone monitor well, which involved close coordination with FDEP staff, as well as design of specialized fishing tools and techniques to remove obstructions from the well. Johnson Engineering permitted an additional injection well capable of injecting 7.9 MGD and oversaw the construction and testing of a new dual-zone monitor well used to monitor zones from 1,502 to 1,562 feet and 1,731 to 1,781 feet.
Johnson Engineering performed a hydrogeological investigation of the Lower Tamiami Aquifer for Treviso Bay that included the construction and testing of over 15 wells and two 48-hour aquifer performance tests were completed as part of this investigation. Inflatable packer testing was utilized in the test wells to isolate discrete portions of the aquifer to determine the location of the saltwater/freshwater interface. Based on the results, Johnson Engineering helped permit residential and golf course irrigation at the site utilizing Lower Tamiami and lake system withdrawals and designed the wellfield. A recent permit modification added the Mid-Hawthorn and Lower Hawthorn aquifers as alternative water supply sources for use during water restrictions. Johnson Engineering implements ongoing water level and water quality monitoring programs at the site.This project included design, testing, and construction of an Upper Floridan aquifer test well completed to a depth of 1,200 feet bls, an Intermediate aquifer well, and a Surficial aquifer well at Babcock Ranch Preserve in Charlotte County for development of a public water supply wellfield for Charlotte County Utilities. Testing of these wells included full suite geophysical logging and three-day constant rate pumping and recovery tests. Data collected from this investigation was analyzed and will be used to design and permit a 3 MGD public water supply wellfield through the South Florida Water Management District.
Charlotte County – Rotonda ASR Well Construction Administration Services
This project involved construction administration services for a project designed by others for a reclaimed water aquifer storage and recovery system with associated wells, piping, pumps, and controls. Our team reviewed the proposed construction plans and provided recommendations for significant cost savings that the County was able to realize. Following on-site testing, including test well construction, geophysical logging and water quality sampling, our results showed the site was not a viable location for a reclaimed water aquifer storage and recovery system.
Charlotte County – Hydrogeological Investigation
This project included design, testing, and construction of an Upper Floridan aquifer test well completed to a depth of 1,200 feet bls, an Intermediate aquifer well, and a Surficial aquifer well at Babcock Ranch Preserve in Charlotte County for development of a public water supply wellfield for Charlotte County Utilities. Testing of these wells included full suite geophysical logging and three-day constant rate pumping and recovery tests. Data collected from this investigation was analyzed and will be used to design and permit a 3 MGD public water supply wellfield through the South Florida Water Management District.
Silver Lake Utilities
Johnson Engineering prepared an engineering report to support certification through the Public Service Commission for a new water and wastewater utility serving portions of Highlands and Glades Counties. In related efforts, Johnson Engineering performed a hydrogeological investigation for a 3,500-unit development in western Glades County, including construction of Sandstone, Hawthorn and Upper Floridan aquifer test wells. Johnson Engineering provided fulltime construction observation and conducted long duration APTs on the Hawthorn and Upper Floridan aquifers. The investigation revealed a highly productive zone of the Hawthorn group suitable for potable water supply with minimal treatment. Data from the testing program was used in development of groundwater models to aid in layout and conceptual design of PWS and irrigation wellfields. Johnson Engineering has performed other hydrogeological investigations for Silver Lake Utilities in Brighton, Moore Haven, Tasmania and Lakeport.
Johnson Engineering evaluated the community’s existing Lower Tamiami PWS wellfield by conducting a 72-hour aquifer performance test while the allowing the wellfield to remain operational, and has assisted in acidization of irrigation wells, irrigation well rehabilitation, and shallow aquifer hydrogeologic mapping and water level assessment and associated groundwater flow modeling. Services for Ave Maria have also included hydrogeological investigations of the Sandstone and Mid-Hawthorn aquifers as alternative water supply options. This effort has involved test well design and construction, aquifer performance testing and water quality analysis. Johnson Engineering has prepared several renewals and modifications of SFWMD irrigation and dewatering permits as the community continues to grow and implements the water level monitoring for permit compliance.
Lee County Port Authority
In response to sinkhole activity concerns at Southwest Florida International Airport, Johnson Engineering evaluated past occurrences of vertical erosions at the site and assessed the potential for future problems due to long term water level changes. The evaluation involved investigating environmental conditions surrounding past occurrences, reviewing historical changes in natural features, and conducting hydrologic analyses to develop a water budget for the site. Johnson Engineering also prepared an investigation on the potential to use the nearby LCPA Mitigation Park as a groundwater-to-groundwater ASR system to provide raw water to Lee County Utilities water treatment plants and then prepared a preliminary design based on the findings.
Byran Paul Citrus
Johnson Engineering has assisted Bryan Paul Citrus in numerous agricultural water use permitting efforts in the SFWMD and SWFWMD for various sites in Highlands, Polk, Charlotte, DeSoto, Hendry and Collier Counties. Among these projects, Johnson Engineering helped renew and modify the 61 MGD LaBelle Private Drainage District SFWMD permit for withdrawals from the Townsend Canal, which included performing a falling head test on the 7-mile-long Header Canal to assess system efficiency and providing calibration for a 153,000 gpm pump station. Renewal and modification of the Doe Hill SWFWMD permit involved permitting over 50 Floridan aquifer wells in the SWUCA.
Hendry, Glades and Fort Myers Water Supply Facilities Work Plans
Johnson Engineering prepared 10-Year Water Supply Facilities Work Plans for Glades and Hendry Counties and the City of Fort Myers, in fulfillment of DCA requirements. Plan preparation involved close coordination with utility providers, private developers, and other governmental entities within these counties and municipalities regarding, among other issues, interlocal provision of water service, and changing population projections and utility expansion schedules brought about by recent economic circumstances. Johnson Engineering assisted in DCA ORC report responses, helped draft policies and ordinances, and participated in meetings with regulatory agencies and adoption hearings.