Water usage has been a concern in other states where deep well drilling and hydrofracing have generated both a demand for large quantities of water and resulting waste fluids that require removal and treatment. The millions of gallons of water required for drilling and the associated waste products are also major concerns here in Pennsylvania. Like in other states, the source of water used in drilling raises an issue, as do the waste fluids, their treatment and disposal, and natural bodies of water in the vicinities of drilling activity and the communities tied to them.
The Susquehanna River Basin Commission regulates significant water use within its jurisdiction, and recently ruled that companies can purchase water from other permitted users with excess capacity without prior approval of the SRBC, provided the total amounts used do not exceed the permitted quantity.
- The result has been widespread interest among natural gas companies in purchasing water from municipal water systems and other already permitted users.
- If approached by such a company, municipal water systems need to carefully consider how much surplus capacity they can sell without jeopardizing other users or other future water dependent economic development opportunities.
One of the primary water concerns with deep gas well drilling technologies is the withdrawal of large volumes (millions of gallons) of water, used mostly in the hydro-fracturing process. The volume of waste fluids produced during gas well drilling and operation can vary considerably depending on the depth and location of the gas well.
One study in Pennsylvania found that the average volumes of water produced during shallow gas well drilling in western Pennsylvania was 25,000 gallons during drilling, 50,000 gallons during stimulation, and 150 gallons per day during production. Newer technologies that rely more on hydro-fracturing the deeper gas wells may use more than one million gallons.
- These large water withdrawals may come from many sources (streams, ponds, lakes, etc.) and can have significant effects if not performed carefully. Water withdrawals generally exceeding 10,000 gallons per day require permits, or registration with DEP under authority of the Water Resources Planning Act.
- Withdrawals occurring in the Susquehanna or Delaware River watersheds also require permits from the Susquehanna River Basin Commission or the Delaware River Basin Commission.
- In addition, the Clean Streams Law limits the amount of water that can be withdrawn from streams to maintain sufficient stream flows to protect aquatic life.
These various regulations have all caused the shutting down of gas well drilling operations that failed to acquire the proper permits or exceeded allowable withdrawals from streams.
Erosion & Stormwater
In relation to water concerns, gas well construction involves extensive earth disturbance including roads, drilling pads and pipelines that can speed erosion. Drilling pads alone may be four to six acres in size for deeper gas wells, a larger portion of disturbed earth than shallow well pads.
Various regulations, especially through DEP, are in place to protect surface water and groundwater from erosion and sedimentation due to these disturbances. Erosion and sediment plans require gas companies to use preventative measures such as filter fence, sediment traps, vegetation, hay bales, culverts with energy dissipaters and rocked road entrances to minimize erosion.
- These plans also include a requirement to restore vegetation to the drill site within nine months of well completion by planting grass, trees or crop plots.
- The DEP’s Bureau of Oil and Gas and each individual county’s conservation district oversee the enforcement of erosion and sediment regulations related to gas well operations.
Many residents throughout Pennsylvania voice concerns about private water well and spring contamination that can occur from gas well drilling, but the reality of these fears has shown to be less prominent than assumed.
Data collected thus far from various regulatory agencies responsible for enforcement of gas well drilling regulations indicate that more than 95 percent of complaints received from homeowners suspecting problems from nearby gas well drilling are instead due to pre-existing problems or other land-use activities, such as agriculture.
However, when contamination does occur as a result of drilling, the impacts can vary greatly, and while the instances are low, it is important to be aware of the range of possible complications.
When pollution of private water supplies from gas well activity transpires it is often documented as primarily stemming from absent or corroded well casings on older or abandoned gas wells.
- That does not mean that there are not pollution risks in newer deep well drilling. While the top-hole water from the initial stages of drilling is usually representative of groundwater used for local water wells and springs, the remaining water encountered during gas well drilling (bottom hole, stimulation and production fluids) may be contaminated with various water pollutants.
- Groundwater pollution can result from flooded or leaking brine holding pits that contain bottom-hole stimulation and production fluids from direct discharge of brines to the land surface.
- In the event of these types of mishaps and negligence, pollution can still occur despite the variety of regulations through DEP and the SRBC and DRBC. Some water quality parameters that may occur at high levels in gas well wastes and can impact drinking water quality (either aesthetic or health effects) are barium, chlorides, sodium, iron, lead, manganese, and arsenic.
- When contamination does occur it should be noted that gas well brines are highly mineralized and contain levels of some pollutants that are far above levels considered safe for drinking water supplies. As a result, even small amounts of brine pollution can result in significant impacts to drinking water supplies.
In addition to the pollutants previously listed, other water quality parameters that may be increased due to negligent drilling operations, such as methane migration into water wells, can be found in related publications available through the local Penn State Cooperative Extension office.
Several major agencies have regulatory authority over Marcellus natural gas, and thus can help influence what occurs and its impacts at the local, regional, and state level.