Celebrating 74 years in Business: 1946-2020
  • Land Development
  • Planning & Landscape Architecture
  • Water Resources
  • Environmental
  • Surveying & Mapping
  • Transportation
  • Utilities

Hydrogeological Investigations

Florida’s geology has historically driven the locations of population centers and economic development by imparting valuable natural resources, groundwater being one of the most vital. The presence and quality of groundwater and other hydrogeological characteristics occurring across a project site can help determine the most suitable and economically optimal uses. Johnson Engineering’s water supply professionals specialize in conducting hydrogeological investigations to determine what lies beneath the ground surface. Investigations may include construction of one or more wells from 10 feet to over 1,000 feet deep, testing of the hydraulic properties of the aquifers through long-term pumping tests, slug tests and falling head tests, and water quality sampling and analysis. We will design, implement and oversee the most appropriate type of testing program for a client in order to gain invaluable data to be used for site and water supply system design, and aid in regulatory permitting.


Water Resource Assessments

Whether it’s a large scale golf course development, a multi-thousand acre agricultural project, or a smaller commercial site, all projects must identify sources of water to supply their irrigation, potable and other water demands. Johnson Engineering draws upon a wealth of both in-house and publically available resources to determine the most economical, reliable and best quality source of water to meet a project’s needs. Sources may range from utility water to surface water or groundwater to seawater desalination, or a combination of sources, depending on the project’s location and particular requirements. The results of the assessment can be used to assist in system design and regulatory permitting.


Water Use & Water Supply System Permitting

Johnson Engineering’s water supply team works with local, state and federal permitting agencies on an array of projects on a near daily basis and has participated in more than a thousand permitting exercises over the past 20 years. Our experience ranges from landscape irrigation for small community associations to potable water supply, irrigation and dewatering permitting for existing and proposed developments of several thousand units, and virtually everything in between. This variety of experience gives us a unique understanding of the agencies, their staff and their rules. Our continual contact with agency staff and the permitting process allows us to stay current on permitting changes and rule development. This enables us to help our clients by updating them on policy changes that could impact their projects and allow them to actively participate in rule development as stakeholders.


Well & Wellfield Design

Not all wells are created equal. A good well or wellfield design goes a long way in achieving optimal well yield and water quality, and minimizing well inference and maintenance and operations costs over the life of a water supply system. Johnson Engineering’s water resources engineers specialize in complex and innovative well, wellhead and wellfield designs, often drawing on their own construction experience as licensed water well contractors. We have designed wells and wellfields capable of withdrawing 10 gpm from a single well up to 20 MGD from dozens of wells and multiple aquifers. We can also develop well rehabilitation or abandonment plans for existing wells, including well acidization, backplugging, mechanical scrubbing, and lining and casing repairs to improve water quality, increase well efficiency and prevent unwanted interaquifer water transfer.


Regional Water Supply Planning

In recent years, the State of Florida has recognized the importance of properly planning for and managing water supply on regional scales. This effort falls not only on the State agencies themselves, but also on Counties, municipalities and developers, as required by law or when amending comprehensive plans or applying for developments of regional impact (DRI). We can assess the most sustainable and economical sources to accommodate future growth and regulatory requirements, prepare conceptual system designs, and identify necessary infrastructure upgrades and financing options for both existing and proposed systems. We have participated in all levels of Water Supply Facilities Work Plans, DRI applications and comprehensive plan amendments to best serve our clients’ short- and long-term goals.


Borehole Logging & Geophysical Evaluation

Borehole geophysical logging provides both direct and indirect evaluation of well casing and the geologic formations in which they are constructed. Video logging allows us to actually observe the inside of a well to ascertain its construction and the nature of the water bearing zones. Other methods, such as acoustic, dual induction, gamma and temperature logs, indirectly characterize the properties of the aquifer and site lithology. Johnson Engineering’s water supply team has extensive experience conducting and overseeing geophysical logging operations, and interpreting logs to aide in making sound decisions related to water quality and well design. We also maintain our own in-house video logging equipment capable of fitting inside a 2-inch pipe. Geophysical data are routinely used to determine the best well construction specifications and address regulatory concerns.


Deep Injection Well Permitting & Mechanical Integrity Testing

Deep well injection is commonly used throughout Southwest Florida to dispose of excess wastewater effluent and concentrate resulting from water treatment processes. Design, permitting and mechanical integrity testing (MIT) of these wells requires both an intimate knowledge of local hydrogeology and well construction techniques. Johnson Engineering’s water supply team has assisted in the permitting and design of new injection wells across the area, and has assisted in the operation permit renewal and mechanical integrity testing of several more. We are adept at conducting casing pressure tests, and high resolution temperature, video and radioactive tracer surveys. Our extensive experience with well construction, geophysical logging and testing allows us to successfully resolve problems encountered during MIT and construction, and interact with regulatory staff.


Groundwater Modeling

Many regulatory agencies require some form of modeling to provide assurances that proposed water uses will not adversely impact surrounding users of the source or natural systems. Modeling can also be a valuable tool for clients in properly designing wellfields and assessing the potential for water quality changes over time, which will help ensure optimal function of water supply systems and aid in management decisions. The right model for a given project may be a simple analytical spreadsheet calculation or a multi-layer, calibrated numerical model incorporating both surface water and groundwater components. Johnson Engineering’s water supply team understands which modeling approaches will best address a particular issue and can develop scientifically defensible models to examine any number of questions and scenarios.


Florida Public Service Commission Certification

Becoming certificated through the Florida Public Service Commission (PSC) offers clients with access to valuable water sources the ability to economically supply service to customers who may lack such resources. Johnson Engineering has worked with teams of attorneys and accountants to help certificate new water and wastewater service franchises covering hundreds of thousands of acres across the State of Florida. We can prepare PSC-required engineering reports, inventory existing facilities, prepare conceptual system designs and costs, help clients identify appropriate categories of service, help demonstrate demand for a given service territory and interact with PSC staff to establish service options and rates in the best interests of our clients and their customers.


Nutrient Loading Evaluations for Water Quality Credits

Florida’s Department of Environmental Protection (FDEP) has a Total Maximum Daily Loads (TMDLs) program to improve water quality for State or federally identified impaired water bodies, including the Caloosahatchee Estuary and Imperial River. The FDEP requires local governments to participate in mandated Basin Management Action Plans (BMAPs) to reduce loadings to these water bodies.

To help BMAP stakeholders achieve their load reduction goals, FDEP developed the ArcNLET software for evaluating septic system effluent in Florida. Johnson Engineering developed the first application of ArcNLET for a south Florida location.

The ArcNLET software is a GIS-based application that evaluates nutrient loadings to groundwater from septic systems. Primary inputs to the model include locations of existing septic systems, hydraulic gradients, effective porosity, and denitrification decay coefficients. Application of the model in areas characterized by low hydraulic gradients with numerous canals and surface water features, typical of south Florida, can pose a challenge. Johnson Engineering has worked in conjunction with the software developer and FDEP to modify model inputs more appropriate for south Florida conditions.


Alternative Water Supply/Reclaimed Water Feasibility Study, Permitting, Funding and System Design

As freshwater supplies across the State become more limited, regulatory agencies have placed increasing emphasis on the development of alternative water supplies to meet a project’s needs and, in some instances, provide incentives for their use. Johnson Engineering can help identify and develop alternative water supplies for both existing and proposed projects. Such services may include feasibility assessments, conceptual to construction designs, permitting, alternative water supply grant funding assistance, and on-site construction observation and administration. Potential alternative supply sources may include reclaimed water, tailwater recovery, brackish or saline groundwater, and seawater desalination. Our professionals help clients determine which, if any, of these options best meets their needs given a particular project’s site constraints, with consideration given to cost, storage and seasonal availability.