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The Pennsylvania Ground Water Association Is Developing A Statewide Model Drilling Ordinance for Pennsylvania’s Municipalities By Todd Giddings, Ph.D., P.G., IGSHPA Accredited Trainer and PGWA Statewide Model Drilling Ordinance Workgroup Chairman Reprinted from the Third Quarter 2010 Pennsylvania Driller Newsletter of the Pennsylvania Ground Water Association
The Pennsylvania Ground Water Association’s (PGWA) Board of Director’s, at their June, 2010 meeting, created a workgroup (composed of 6 directors) that will take the Spring Creek Watershed’s Model Drilling Ordinance (which is tailored to a carbonate terrain) and rewrite and expand it into a Statewide Model Drilling Ordinance that will apply to all of the rock types and hydrogeologic settings throughout Pennsylvania. In the first quarter 2010 issue of this newsletter, in an article titled “The Spring Creek Watershed New Drilling Ordinance Story”, I told you the story of why and how a new drilling ordinance was developed for the Spring Creek Watershed in Centre County and how the ordinance was going to be implemented. Later in this article, I describe how the actual implementation of the Spring Creek Model Drilling Ordinance took place for both new and in-progress geothermal heat pump system projects. This model drilling ordinance story has its roots back in 2007 when geothermal heat pump systems were becoming more popular, and water-well drillers were growing their drilling businesses by drilling geothermal boreholes for close-loop geothermal systems. I wrote an article in the fourth quarter 2007 issue of this newsletter titled “Geothermal Heat Pump Systems Are Becoming More Popular, So What’s the Problem?” The problem was (and still is) that many drillers, new to the geothermal borehole drilling industry, were not properly grouting the loop pipes in the boreholes to protect the groundwater quality and provide thermal conductivity between the bedrock of the borehole wall and the loop pipes. Pea gravel, sand, and drill cuttings were being used to backfill the boreholes around the two loop pipes because these materials were very cheap, and were easy and quick to install, and a grouting machine was not needed. Photo below: Sand from the pile was the only material used to backfill the 36 boreholes in this loopfield. The coils of pipe are the ends of the loops in each borehole.
On the Spring Creek Watershed geothermal loopfield site shown in the photograph, the sand in the pile (in this case limestone crushed down to sand-sized grains) was put into the boreholes simply by using a small, rented skid-steer bucket-loader. There was no concern about any bridging of the sand in the borehole creating air pockets, the low thermal conductivity of the dry sand above the water table, and the direct flow pathway that the sand created for contamination to enter the aquifer. The sand-filled boreholes on the site shown in the photograph are located within the Zone II Area (capture zone area of direct groundwater flow to a well) of a nearby municipal water-supply well.
The next stage in this saga began on October 3, 2008, when the 700 billion-dollar bailout legislation was signed into law. This legislation, called the Emergency Economic Stabilization Act of 2008 (H.R. 1424), also contained long-term tax incentives to encourage the use of renewable energy technologies in both homes and businesses. The energy technologies included solar electric generation, fuel-cell electric generation, wind electric generation, and geothermal heating and cooling. In the fourth quarter 2008 issue of this newsletter, I wrote an article titled “New Geothermal Tax Credits Create a ‘Perfect Storm’ in the Geothermal Industry” that described how a) the demand for “green” heating and cooling systems; b) the long-term increasing costs of propane, natural gas, and heating oil; and c) the new Federal geothermal tax credits together created a boom in the geothermal industry that has been called a “perfect storm” of unprecedented demand for geothermal heat pump systems. The “perfect storm” for geothermal heat pump system demand quickly hit the 175 square-mile Spring Creek Watershed (hereinafter Watershed) in Centre County with its full force. Within this watershed, more than 99% of its 100,000 residents have groundwater as their water source. The number of geothermal heat pump system closed-loop boreholes that were (and are currently) being drilled were (and still are) at least ten times the number of new house wells being drilled. Many of the improperly constructed (ungrouted) geothermal boreholes were located within the capture zones of many municipal water-supply wells. In response to the concern of the watershed’s residents about the potential to contaminate the groundwater that was the source of their drinking water, the Spring Creek Watershed Commission formed a workgroup that created the model drilling ordinance. Photo below : Centre Regional Code Agency Walter Schneider (left) is holding the Residential Geothermal Borehole Permit No. 0001 with Chris Exarchos, President of GeoEnergy, Inc., the company that installed the retrofitted geothermal system.
Within several municipalities in the watershed, the ordinance went into effect in June, 2010, which was only one year after this groundwater quality protection effort started. Four municipalities have implemented the model ordinance through their shared Centre Regional Code Agency in a new chapter of their regional building code dealing with property maintenance and safety. The photograph shows the Code Agency Director Walter Schneider (left) holding the residential geothermal borehole permit No. 0001 with Chris Exarchos, President of GeoEnergy, Inc., the company that installed the retrofitted residential geothermal heat pump system. A large geothermal borehole loopfield was under construction at a renovation project on an elementary school when the model drilling ordinance went into effect, so a change order was implemented to bring the borehole grouting into compliance with the new construction standards. The Regional Code Enforcement Office, the loopfield design engineer, the mechanical contractor, the school district, and the borehole drilling contractor all worked together to make this compliance change happen during an active loopfield construction project. This loopfield is located within the capture zone of a very high capacity municipal well field that serves State College Borough and the surrounding urban area. Photo below: The grouting requirements for the geothermal boreholes in this commercial loopfield at an elementary school were modified by a change order to bring them into compliance with the new construction standards.
The other municipalities in the Spring Creek Watershed are currently in the process of adopting the model drilling ordinance as a stand-alone local ordinance that will be administered and have site inspections done by municipal employees and/or contract personnel. While the driving force behind this model ordinance was the geothermal “perfect storm”, the model ordinance (and the property maintenance chapter) both contain construction standards for residential water-supply wells that specify the casing depth and casing material, and require grouting of the annular space around the well casing to protect the groundwater quality. It was only the overwhelming number of new geothermal boreholes being drilled every day that led to their prominent role in this success story. The proper construction of new residential water wells, including the grouting of the annular space around the well casing, is no less important than geothermal borehole grouting for the protection of the groundwater quality within the Spring Creek Watershed and throughout Pennsylvania.
Reprinted from the Third Quarter 2010 Pennsylvania Driller Newsletter of the Pennsylvania Ground Water Association
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