The Moody study, commissioned by the conventional oil and gas industry, studied whether land application of conventional oil and gas wastewater exceeded the 250 mg/l of chloride standard DEP had established for adverse impacts to groundwater approximately 50 feet from the point of discharge.
The industry study selected ten individual operating wells sites that were in operation for a minimum of ten years where wastewater from the wells was discharged to the land surface or into unlined pits adjacent to the wells.
A total of 51 monitoring wells were installed at ten locations and located up and down gradient from the point of discharge in both shallow and next deeper groundwater flow systems.
Soil moisture lysimeters were also installed downgrading at eight of the sites.
The monitoring wells were sampled during both the wet and dry periods of the year-- April and July. The lysimeters were sampled during December and May.
All groundwater and soil moisture samples as well as wastewater samples from each well were submitted to DEP's laboratory for analysis of the major chloride salt compounds, heavy metals, selected organic compounds and general chemical parameters.
Study Results
Seven of the ten sites exhibited significant shallow groundwater impacts as defined by chloride concentrations in excess of 250 mg/l in a downgrading direction in the shallow or deep groundwater flow systems, according to the study..
The study found chloride/salts concentrations averaged 1,384 mg/l, but ranged up to 7,598 mg/l at some sampling sites. [page 27]
The original concentrations of chlorides in the wastewater from the test wells averaged 35,855 mg/l, and ranged up to 57,700 mg/l. [page 6]
Four of the eight monitored sites exhibited significant impacts to soil moisture.
Iron, manganese and barium were found in increased concentrations in the downgrading wells at six of the ten sites.
Oil and grease concentrations increased in four of the ten sites, while no increases in benzene concentrations were noted at any of the ten sites.
The study concluded, "The water quality data generated from this study indicates that the long term discharge of shallow oil field produced water [oil and gas wastewater] to the ground surface is not a viable management practice." [page 26]
The study is interesting because it was done in 1997.
Click Here for a copy of the Moody study.
Road Dumping
These study results are relevant to the controversy today over the road dumping of conventional oil and gas wastewater as a disposal method.
The repeated and heavy road dumping of conventional oil and gas wastewater that continues on Pennsylvania dirt and gravel roads and amounts to the repeated "ground surface" application of oil and gas wastewater evaluated in the Moody study.
The 250 mg/l limit of chlorides in groundwater contamination limit DEP established for the Moody study is significant because a Penn State study released in May 2022 found water runoff from conventional oil and gas wastewater dumping on dirt and gravel roads contained from 7,550 to 10,000 mg/l of chlorides. Read more here - page 50.
The original chloride content of the oil and gas wastewater tested in the latest Penn State study contained from 47,900 to 49,700 mg/l of chlorides. Read more here - page 39.
Penn State found the amounts of at least 25 of the 31 chemicals they tested for exceeded environmental and health standards and radioactive radium exceeded industrial waste discharge standards. Read more here.
At a Senate hearing on April 17, Dr. William Burgos, lead author of this and other related Penn State studies said, "Pennsylvania should ban road spreading" of oil and gas wastewater based on this and other studies he and his team had done because of its potential for environmental and health impacts. Read more here.
“There is no public benefit to road spreading O&G PWs [oil and gas wastewater]…. It is all risk, no reward. The only beneficiaries are the O&G [oil and gas] operators who choose this disposal option,” Dr. Burgos concluded. Read more here.
Road dumping of wastewater from unconventional shale gas wells is already banned under regulations DEP adopted in 2016. [25 Pa Code Chapter 78a.70]
Another Penn State study concluded there were not a lot of differences between conventional and unconventional wastewater, according to Dr. Burgos. Read more here.
DEP's Oil and Gas Program settled an Environmental Hearing Board appeal in 2017-18 by agreeing not to approve any road dumping plans by conventional operators. Read more here.
However, conventional wastewater could still be road dumped under DEP's Waste Management Program's Coproduction Determination process in 25 Pa Code Chapter 287, but no conventional well owner has met those requirements yet. Read more here.
Disposal Of Wastewater
The Moody study results are also relevant to DEP’s effort to update conventional oil and gas regulations for waste management and disposal.
DEP's current conventional oil and gas regulations contains a blanket provision saying-- "the operator may not discharge the brine or other fluids on or into the ground or into the waters of this Commonwealth," except as allowed in Chapter 78 "or otherwise approved by the Department." [25 Pa Code Chapter 78.57]
The conventional regulations also contains another blanket provision saying a well owner "may not cause or allow a discharge of a substance to the waters of the Commonwealth," unless it complies with Water Quality Regulations and the Clean Streams Law. [25 Pa Code Chapter 78.60]
"Waters of the Commonwealth," are defined in the Clean Streams Law as "any and all rivers, streams, creeks, rivulets, impoundments, ditches, water courses, storm sewers, lakes, dammed water, ponds, springs and all other bodies or channels of conveyance of surface and underground water, or parts thereof, whether natural or artificial, within or on the boundaries of this Commonwealth.
This includes roadside ditches and related artificial drainage channels.
In addition, the well owner may not discharge tophole water or water in a pit as a result of precipitation by "land application" unless the water is free of "pollutional materials," there is no sheen from oil and grease and the water is spread over an undisturbed, vegetated area capable of absorbing the tophole water, filtering solids in the discharge and spread in a manner that prevents direct discharge to surface waters or within 100 feet of a stream, body of water or wetland. [25 Pa Code Chapter 78.60]
Clearly, road dumping conventional wastewater on a dirt or gravel road would meet none of these requirements for tophole water land application.
Moody Study Supports Bans
Looking at the conclusions in the Moody study-- "The water quality data generated from this study indicates that the long term discharge of shallow oil field produced water [oil and gas wastewater] to the ground surface is not a viable management practice” and multiple Penn State studies, there is support for both a--
-- Ban on the onsite disposal of conventional oil and gas wastewater; and a
-- Ban on the road dumping of conventional wastewater.
Resource Links:
-- Senate Hearing: Penn State Expert: ‘No More Research That Needs To Be Done’ To Justify A Ban On Road Dumping Conventional Oil & Gas Wastewater [PaEN]
-- Senate Hearing: First-Hand Account Of Health, Environmental Impacts From Road Dumping Conventional Oil & Gas Wastewater - ‘Inhaling Oil & Gas Wastewater 24-Hours A Day’ [PaEN]
-- Senate Hearing: The Case For An Immediate, Total Ban On Road Dumping Conventional Oil & Gas Wastewater [PaEN]
-- Senate Hearing: 3.5 Million Gallons Of Conventional Oil & Gas Wastewater Dumped On PA Public Roads Since DEP’s ‘Moratorium’ On Dumping Started 6 Years Ago [PaEN]
[Posted: May 7, 2024] PA Environment Digest
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