COUNTY OF SUFFOLK STEVEN BELLONE SUFFOLK COUNTY EXECUTIVE SUFFOLK COUNTY PLANNING COMMISSION DAVID L. CALONE CHAIRMAN SARAH LANSDALE, AICP DIRECTOR OF PLANNING November 2014 SUFFOLK COUNTY MODEL GEOTHERMAL CODE OVERVIEW MEMO Code developed and adopted by the Suffolk County Planning Commission in conjunction with the Long Island Geothermal Energy Organization (LI-GEO) and based upon an initial code developed by the Town of Brookhaven. The code incorporates the input of key stakeholder entities including the NY State Department of State s Division of Building Standards and Codes, the NY State Department of Environmental Conservation (DEC), the Suffolk County Legislature, the Suffolk County Department of Health Services (SCDHS), the Suffolk County Water Authority (SCWA) and Renewable Energy LI (reli). The global imperative to increase energy efficiency, reduce energy costs and reduce carbon emissions is growing. Numerous renewable energy producing and energy efficiency technologies are being rapidly developed and introduced to achieve these goals. Aside from environmental benefits, these emerging technologies also provide economic benefits, as they create new jobs to design, manufacture and install the new equipment in residential and commercial settings. Geothermal energy technology is rapidly emerging as a preferred energy efficient and environmentally friendly means of heating and cooling residential and commercial buildings as it reduces the usage of fossil fuels and lowers energy consumption and costs. On Long Island, the installation of geothermal systems has been steadily increasing and will only accelerate as new incentives kick-in under PSEG Long Island s Utility 2.0 plan. Building on previous nationally-recognized efforts to create municipal solar and wind model codes, the Suffolk County Planning Commission has developed and endorsed a model geothermal code to help municipalities evaluate proposed geothermal systems in residential and commercial settings. This memo provides an overview of several key aspects of that code.
THE MODEL CODE This model geothermal code is designed to remove the complexity and hassle of installation approvals by identifying relevant municipal concerns, identifying standards to be used in all installations, and allowing for a more streamlined code and application process that is at once more relevant and more targeted than current building codes and permit processes. The model code applies to typical systems installed in non-sensitive areas (see Code Section 2(B)(g)), which comprise the majority of situations in which geothermal systems are being installed on Long Island. The code seeks to inform an approval process that will ensure that the permit process is tailored to provide the municipality with all relevant information and to meet its municipal requirements while being swift and predictable for applicants. The model code is designed to be flexible and adaptable for individual municipal needs and concerns, and to serve as a starting point to guide municipal review, approval and installation of geothermal systems. This model code sets up basic design, construction, certification, and installation standards developed by government and private industry in Suffolk County, and will help set up a basic review process a municipality should follow, along with identification of the various national standards that should be followed and certifications necessary. The code is designed to allow for conceptual approval of the system and allow it to be reviewed by a building inspector and be subject generally to just a simple building permit. BASIC TYPES OF GEOTHERMAL SYSTEMS Geothermal systems are essentially ground source heat exchange systems used for both heating and cooling of indoor spaces and, in some instances, production of domestic hot water. The systems use a working fluid circulated in underground piping to tap into the latent heat potential that exists underground in soil and aquifers, and brings that potential above ground to exchange the heat energy with indoor distribution systems. The vast majority of geothermal systems (also known as Ground Source Heat Pump Systems), available today fall into three categories which are distinguished by the type of ground heat exchanger installed in the earth for heat transfer: Closed Loop, Open Loop, and Direct Exchange. A CLOSED LOOP SYSTEM uses buried high density polyethylene (HDPE) plastic piping installed in drilled and grouted boreholes that exchanges thermal energy with the ground via circulating water or a water/antifreeze mixture through the piping and then on to a heat transfer system for further distribution. An OPEN LOOP SYSTEM involves a series of standard water wells that extract and pump groundwater from the aquifer directly to the above-ground heat transfer equipment and then return the water back into the ground. A DIRECT EXCHANGE SYSTEM uses buried copper tubing that absorbs heat energy from the ground either via direct exchange-to-earth contact or through direct exchange-to-water contact by continuously circulating a refrigerant through the tubing to above ground heat transfer equipment.
PLACEMENT OF SYSTEMS Closed Loop and Direct Exchange systems may be installed vertically in drilled boreholes or horizontally in excavated trenches that are then backfilled. Open Loop systems are essentially wells that are installed vertically in drilled boreholes that reach for groundwater. Direct Exchange and Closed Loop systems that are installed horizontally may take up considerable land areas and pose setback issues in densely developed areas. PERMIT STRUCTURE OF CODE The model code is designed to be administered by a municipality utilizing a standardized permit application process. The code is designed to allow fast track permitting if stringent requirements and criteria are met up front by the applicant. Permit applications should include general documentation such as site plans, plot plans on surveys, identification of the type of system to be installed, setbacks, etc. Each of the three main types of geothermal systems has different compliance and certification requirements, including differences in who certifies installation of equipment and which national standards are involved. Specific information required includes certifications of an engineer for design of certain systems, compliance by an installer with municipal certifications, certifications of compliance with relevant industry standards by the installer, and compliance with local construction codes, etc. OTHER REGULATORY AGENCIES Depending upon equipment used and locations, other governmental agencies may also be involved in the permitting process. This model code includes the SCWA s request that they be notified of the installation of open loop systems in order to track the potential influence that pumping from these systems may have on SCWA well capture zones. A Long Island Well Permit is required from DEC for sites where proposed open loop systems are proposed that will pump greater than a certain volume of water. When geothermal systems are proposed in conjunction with sewage disposal and or water supply facilities, the geothermal system is also subject to SCDHS rules contained in the SCDHS GENERAL GUIDANCE MEMORANDUM #25 -- GUIDELINES REGARDING THE USE OF GEOTHERMAL WELL SYSTEMS GENERAL CONSTRUCTION REQUIREMENTS Open Loop systems using water wells must protect the aquifer and the equipment involved. The pumping and recharging flow rate, which determines the lowering (cone of influence) and rise (mounding) of groundwater around the wells, is a critical design element for large systems, and is reviewed by DEC as part of the Long Island Well Permit process. Geothermal supply wells cannot be cross-connected to potable water systems or septic systems. Water extracted must be returned to the same aquifer. The natural depth to the aquifer (water table) must be at least 20 feet deep. Pumping of potentially polluted groundwater is not covered in the code, but is reviewed and assessed by DEC for large Open Loop systems as part of the Long Island Well Permit process. Closed Loop systems and Direct Exchange systems require high density piping and grouting of vertical boreholes through the full depth of the aquifers and careful backfilling of the horizontal piping in trenches to prevent damage to the piping. Since aquifers in Suffolk are very vulnerable
to groundwater contamination due to porous soils, comprehensive and redundant pressure testing of all the buried piping is required to ensure the integrity of piping and joints. DESIGN STANDARDS Basic national standards exist for each type of system described in and made mandatory by the model code. These system standards are keyed to the American Society for Testing and Materials (ASTM) and American Society of Mechanical Engineers (ASME) national standards, but there are further individual standards for each person involved in design and installation for each type of system that are also keyed to separate industry standards. ENVIRONMENTAL ISSUES The model code is designed to provide environmental protections for typical systems installed in non-sensitive areas. Among the special environmental requirements in the model code for certain situations are: -adherence to SCDHS rules when open loop systems are to be installed near septic systems. -limiting the types of antifreeze additives that may be used in Closed Loop systems. - water return for Open Loop systems must not cause harm to the environment, must return to the aquifer from which it came, must not introduce chemicals to the ground water, and must prevent aeration of the water table which can cause iron buildup or other plugging of well equipment and piping. In addition, per DEC rules, the return water cannot be discharged into sanitary or storm sewers or septic systems but may go into waterways if permitted by the State DEC, SCDHS or the municipality. - mechanical equipment for Open Loop systems must be compatible with the groundwater chemistry. -as a general standard any water draw down around extraction wells should not cause harm to the environment or impact existing water supply wells. Municipalities should take a harder look at installations proposed to be installed in areas of potential sensitivity (see Code Section 2(B)(g)). Because of the extra risk that system failure can have on the natural environment in these areas, municipalities should consider not allowing systems in these areas or increasing required setbacks. Other regulatory agencies may also impose additional reviews and restrictions in these areas. Although safeguards are provided in this model code, another area that municipalities may wish to address further is the protection of water supply wells from possible contamination, thermal impacts (heating groundwater when returned to the aquifer in an Open Loop system, or thermal impacts from heat exchange in vertical systems) or water/aquifer level draw down. The latter is a concern of the SCWA and is the reason that notification to the SCWA is required for Open Loop systems.
SETBACKS Setback/separation of various distances are established in the model code in order to assure proper operation of geothermal systems. These setbacks are dependent both upon the type of geothermal system and any structure or environmental feature nearby. For instance, systems must be setback 100-200 feet from public water supply wells, 25-100 feet from private wells, 25-50 feet from sanitary and storm water disposal structures(to assure non contamination from septic systems, recharge structures, storage tanks, etc.), and 10 feet from building foundation and property lines. The code provides for professional review and certification of these setbacks at the discretion of the municipality.