The US Environmental Protection Agency released a progress report on a long-term study into the effects of hydraulic fracturing on groundwater.
The American Petroleum Institute called the report a "first step" but said the EPA had begun "constructive course corrections" in its efforts to get to the bottom of a burning controversy.
The EPA report lays out a framework for how the agency will proceed with the highly anticipated study, which will not be finalised until 2014.
There are 18 individual studies currently ongoing that will make up the larger report after facing a scientific advisory board and extensive peer review.
The studies probe five aspects of the hydraulic fracturing water cycle: water acquisition, including the impacts of the high volume of fluid required for the process; chemical mixing and the potential effects fracking-fluid surface spills; well injection and its potential impact on aquifers; flowback and produced water and the potential for surface spills; and wastewater treatment and waste disposal.
The full report aims to comprehensively address stark disputes surrounding a process that has led to a drilling and production boom in the US and unlocked vast quantities of hydrocarbon resources in shale and other tight deposits. Environmentalists say fracking poses a dire threat to water and air quality.
However, the EPA warned in its update: "Information presented as part of this report cannot be used to draw conclusions about potential impacts to drinking water resources from hydraulic fracturing."
The EPA has extensively culled data from industry, states and disclosures on FracFocus, the website favoured by oil and gas companies to keep track of chemicals used in the fracking process. It has also devised a number of "hypothetical but realistic" scenarios that will be evaluated for insight into what happens at various stages of the fracking cycle.
"Ultimately, the results of this study are expected to inform the public and provide decision-makers at all levels with high-quality scientific knowledge that can be used in decision-making processes," the report says in an executive summary.
Stephanie Meadows, API's upstream senior policy advisor, lauded the EPA's formation of technical roundtables that include industry expertise.
“More collaboration, continued transparency and stakeholder involvement are essential elements for any scientifically sound study, and we hope that the rest of this process remains open and any data released has the necessary context," she said in a statement.
“A robust, thorough, careful study is important because it could affect the future course of shale energy development."
A spokesperson for Water Defence, an outspoken opponent of fracking, did not immediately respond to a request for comment.