Marcellus exploration drives river basin monitoring programs

University Park, Pa. -- Pennsylvania's two largest river basins -- the Susquehanna and the Ohio -- are not just irrigation and drinking-water sources for millions of people downstream. They also have become fountains of information channeling streams of water-quality data to researchers worldwide.

Remote sensors dot these waterways to collect and transmit observations through several networks to regional monitoring outposts, partially in response to the increased intensity of Marcellus shale gas exploration. Additional sensors are being deployed throughout river systems statewide to widen the networks and deepen the data pool in anticipation of increased water use and the potential for widespread contamination due to gas-extraction activities.

Featured speakers will address river monitoring in relation to natural-gas exploration during a free, Web-based seminar titled, "Water Quality Monitoring Programs in PA," which will air at 1 p.m. on June 17. Sponsored by Penn State Cooperative Extension, the "webinar" will provide an overview of two water-quality monitoring networks as shale-gas exploration intensifies across the state's various watersheds.

Information about how to register for the webinar is available at online. Online participants will have the opportunity to ask the speakers questions during the session.

"As the Marcellus industry relates to a footprint in the basin, there is going to be use of a significant amount of water, plus additives and return water that could potentially contain a whole host of contaminants that can affect water quality," said webinar presenter Andrew Gavin, a hydrologist with the Susquehanna River Basin Commission (SRBC).  

"If you're going to get the gas out of the ground, you don't want to ruin your drinking water," added Jeanne VanBriesen, a professor of civil engineering at Carnegie Mellon University. "This is a challenge that permeates the environmental field." VanBriesen, another speaker during the online seminar, is also the director of the Center for Water Quality in Urban Environmental Systems and performs research in conjunction with the River Alert Information Network, an early warning detection system on major rivers in southwestern Pennsylvania.

The Susquehanna River Basin covers about half the land area of Pennsylvania and more than 70 percent of this basin is underlain by the Marcellus Shale, according to the Pennsylvania Department of Environmental Protection. The Ohio River Basin covers slightly less land area in Pennsylvania, but virtually all of it lies above the Marcellus Shale formation. Marcellus Shale also underlies about 36 percent of the Delaware River Basin to the east. 

The SRBC plans to have more than 30 water-quality sensors in place by the end of this month, operating in regions where drilling in the Marcellus shale is most active, according to Gavin. He said the SRBC has operated an early-warning system at drinking-water intakes since 2003 along the main stem of the Susquehanna River between Danville, Pa., and Maryland, and that the larger monitoring network for natural-gas application evolved from that. He said the newer sensors are typically being installed in smaller headwater streams, which are more sensitive to contaminants.

The remote sensors, which can cost up to $20,000 per unit, report data on water temperature, acidity and turbidity, which is a measure of the amount of light that can pass through water to plant and animal life beneath the surface. The sensors also measure levels of dissolved oxygen, an essential element for aquatic life, and conductance, which indicates the amount of dissolved solids in the water.

Gavin noted that to cover the $800,000 price tag for the sensor network, the SRBC invested $250,000 of commission funds, and then received a donation from East Resources Natural Gas Co. for $750,000 to complete the work.

The sensors collect and record data every five minutes and send a summary of that data to the SRBC office every hour. Gavin said they set thresholds for each parameter they monitor, and if a value exceeds that threshold, the system sends notification to several staff members' cell phones. "It's nice to get an e-mail 24-7 when a water quality parameter goes out," Gavin said.

If the system does send out an alarm, Gavin said the standard operating procedure is to first verify whether it is an equipment malfunction, and if the alarm is real, a staff member goes to the alarm site and performs some simple measurements on-site. He said if there is a change in water-quality conditions, his office notifies the Department of Environmental Protection.

He said the sensors haven't detected anything related to natural-gas activity yet, but he marveled at how the stations react to rain events, particularly in the ability to monitor changes in water pH due to acid rain. He said that in a storm event, parameters such as turbidity and conductance fluctuate.

Gavin characterized the monitoring reports as "provisional data," which is available to any other agency, should any action need to be taken, but it is also available to the public.

VanBriesen suggested that we do not sufficiently monitor water in this country.

"We don't have predictive models for water the way we do for weather," she said.  "The world is changing, and most of the ways we have of predicting what is going on in water is based on history."

She said that by studying trends in water quality, we may be able to better predict water quality by observing changes in quality during water events such as floods or droughts. "We also keep the water safe by testing it a lot," she said.

The River Alert Information Network (RAIN) operates an online river-monitoring system to help protect public health and drinking water across southwestern Pennsylvania. The network is a set of 25 to 30 monitoring outposts for drinking-water providers in the region. An estimated 1.7 million Pennsylvania residents rely on the Allegheny, Monongahela, Youghiogheny and Ohio rivers as their sources of drinking water.

In conjunction with RAIN, VanBriesen said she is looking at other water parameters that can't be monitored by real-time sensors. Her group gathers samples from 10 sites along the Monongahela -- six at drinking-water intakes and four at remote sites, including one at Dunkard Creek, the Monongahela headwater that was the site of a major aquatic kill last year, due to a bloom of invasive algae possibly related to a spike in total dissolved solids.

VanBriesen said that waters in southwestern Pennsylvania always have been higher in total dissolved solids, and that there are "many legacies of contamination" in the region. Abandoned mines, mine discharges and high TDS levels, particularly in the fall months during low-flow conditions, were all drivers for the Pennsylvania DEP to put the observation network in place, she said.

She added that Marcellus activity is a main focus for monitoring because local rivers and creeks don't have many "assimilative" qualities. "They can't take much more," she said. "Even if water is appropriately treated, if it's going to be discharged or diluted in local waterways, that is a concern."

One of VanBriesen's greatest concerns is whether the Marcellus shale has higher levels of bromide, because elevated levels could lead to what are known as "brominated disinfection byproducts." Marcellus formations contain small amounts of ancient sea salt and possible traces of bromide.

If source water contains bromide, which is a naturally occurring, nonreactive ion, and that water gets treated with chlorine, it produces bromine, which is a problem. Bromine is a much stronger disinfectant than chlorine, typically used in hot tubs because it is more stable at high temperatures, but brominated disinfection byproducts are a serious problem in drinking water.

"In public drinking-water systems, they take things out -- carcinogens, pathogens and particles," VanBriesen said. "At the very end, they always add chlorine to kill organisms." Problems can arise when chlorine reacts with other organic carbons to produce chlorinated disinfection byproducts that are linked to cancer or reproductive problems.

"So we always have to add enough so that it can disinfect, but not so much that it makes people sick," she explained.

The "Water Quality Monitoring Programs in PA" webinar is part of an ongoing series of workshops addressing issues related to the state's Marcellus shale gas boom. One-hour webinars also will be held at 1 p.m. on the following dates:

July 15: "Natural Gas Development Land Use Controls in Lycoming County"; Presenter: Kurt Hausammann, Lycoming County Planning Commission.

Aug. 19: "Local Natural Gas Task Force Initiatives"; Presenters: Mark Smith, Bradford County; Pam Tokar-Ickles, Somerset County; and Paul Heimel, Potter County.

Sept. 16: "Natural Gas Experiences of Marcellus Residents: Preliminary Results from the Community Satisfaction Survey"; Presenter: Kathy Brasier, Penn State.

Previous webinars, which covered topics such as water use and quality, gas-leasing considerations for landowners and implications for local communities, can be viewed at online.

For more information, contact Joann Kowalski, extension educator in Susquehanna County, at (570) 278-1158 or by e-mail at

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Last Updated November 18, 2010