It is becoming critical to find sustainable solutions to address strains on our water sources. Protecting existing fresh water sources while managing the world's increasing volumes of waste water produced by industrial activity and hydrocarbon production will require innovation. The global market for water treatment is expected to reach $38.2 billion by 2015.
The Environmental Protection Agency's ("EPA") National Pre-treatment Program has led the way to dramatically reduce or eliminate discharges of pollutants to sanitary sewer systems and to the nation's water bodies. The Program controls a complex array of industrial waste streams in order to prevent interference or pass--through of municipal treatment system processes. Without these controls, a number of harmful pollutants could make their way into the nations' waters.
Pollutants in industrial wastewater may compromise municipal treatment plants' processes or contaminate the nation's waters. To protect municipal treatment plants and the environment, the Pre-treatment Program requires industrial dischargers to use treatment techniques and management practices to reduce or eliminate the discharge of harmful pollutants to sanitary sewers.
Industry and businesses use water in many ways to manufacture products and provide services. For example, companies often use water to clean metal parts before they are painted. Companies frequently discharge the resulting dirty water into the same pipes to a municipal wastewater treatment plant. This non-domestic wastewater is often different than wastewater from homes, and may not be adequately treated at a municipal wastewater treatment plant. The word pre-treatment refers to the treatment of non-domestic wastewater before it's discharged to a municipal wastewater treatment plant. The industries that produce metals, wood and paper products, chemicals, gasoline and oils are major users of water. Probably every manufactured product uses water during some part of the production process. Industrial water use includes water used for such purposes as fabricating, processing, washing, diluting, cooling, or transporting a product; incorporating water into a product; or for sanitation needs within the manufacturing facility. Some industries that use large amounts of water produce such commodities as food, paper, chemicals, refined petroleum, or primary metals.
The program controls a complex array of non-domestic wastewater through discharge standards and pollution prevention measures. The non-domestic include high-technology firms in the electronics and aerospace sectors, as well as significant food processing operations. The program is primarily implemented by local municipal pre-treatment programs with assistance and oversight by the states and U.S. EPA. The Pre-treatment Program has dramatically reduced or eliminated discharges of non-domestic pollutants to municipal wastewater treatment plants and the nation's waters.
In 2011 in the United States there were approximately 1,600 publically owned municipal waste water treatment facilities with approved pre-treatment programs. To these roughly 20,630 significant industrial waste water generators deliver billions of gallons of waste water for pre-treatment.
Soaring crude prices and a growing energy demand have pushed the oil and gas industry in recent years to develop "unconventional" hydrocarbon deposits that were once deemed too risky and too expensive to exploit. This sector is now worth billions (between 1999 and 2010, hydraulic fracturing grew from $2.8 billion to $13.5 billion ) but poses some obstacles.
Produced water is water trapped in underground formations that is brought to the surface along with oil or gas. It is by far the largest volume by-product or waste stream associated with oil and gas production. In the United States produced water volumes are currently estimated at ~25 billion bbl./year and anticipated to escalate to ~35 billion bbl./year by 2025. The worldwide estimate is about 70 billion barrels (11.1 billion m3) per year. The primary constituents in produced water that limit its disposal or reuse are: salt content, the presence of organic materials measured as oil and grease, various toxic chemicals, and naturally occurring radioactive materials. Inappropriate produced water management can lead to environmental problems. In mature oil and gas formations, the produced water that is extracted in the production process can be multiples of each barrel of oil produced. In 2007 estimates of water to oil production ratios were:
Worldwide 2:1 to 3:1
U.S. 5:1 to > 8:1
Some older U.S. wells can produce up to 50:1
The problems associated with the storage and disposal of the massive volumes of produced water will continue to grow as the production from unconventional oil and gas sources increase.
Hydraulic fracturing is a well completion technique used to increase oil and gas production. Hydraulic fracturing requires tremendous amounts of fresh water to be used and disposed of. Fracture fluids (primarily water with sand proppants and chemical additives) are pumped into the well under pressure to create fractures in the impermeable formation that will then allow trapped oil or gas to flow to the production well. The oil and gas industry is under increasing scrutiny regarding the potential environmental impacts from hydraulic fracturing.
The application of the fracturing process uses significant quantities of water, with a typical range of two to eight million gallons for a horizontal well, and an average of three million gallons (CLSA, June 2010). Additionally, unconventional wells may need to be fracture-stimulated several times to keep the oil or gas flowing, with each stimulation requiring more water than the previous one.
The availability of water for hydraulic fracturing, given the quantities involved, is essential to support projected growth of unconventional production methods. Water is generally sourced from surface or groundwater that may be publicly or privately held. Regulatory requirements for the sourcing, treatment and disposal of water are important factors shaping both availability and costs for unconventional resource developers.
Other issues associated with handling flow back water include temporary storage and transport prior to disposal or treatment. Flow back water is often stored in lined or unlined open evaporation pits which could lead to seepage into soil resulting in potential contamination. Adoption of advanced water treatment technologies is expected to increase as environmental regulation continues to mount.
Managing produced and flow back water constitutes a huge economic burden and environmental challenge for oil and gas companies. As these problems continue to grow, more stringent regulations governing environmental impact are expected to drive the market for advanced waste water treatment services. As social pressure mounts, oil and gas exploration and production companies are searching for better solutions to these problems.
Primary disposal method: licensed/approved injection sites (injected into underground saline aquifers that underlie many of the shale formations). However the availability of adequate disposal well sites is a major issue currently under review by the industry.
Disposal at waste water treatment facilities
Drilling sites may be too remote to cost-effectively transport flow back water to available treatment facilities. In addition to transportation costs there is also the issue of volume of flow back that would need to be trucked long distances on regional roadways and increased traffic and greater strains on public resources. Also, waste water treatment facilities may be insufficient to handle flow back volume and facilities may not be designed to handle the highly saline flow back water or produced water.
Based on information Ridgeline has compiled, there are few competing technologies that are economically viable processes for treating flow back water and produced water. Other methods, such as distillation (evaporation), membrane filtration (reverse osmosis) or ultrasonic cavitation (sonoluminescence) are effective, but very expensive in infrastructure, energy, and/or operating costs. These methods can have limited bandwidth of treatment or abilities to tailor the water treatment regime for different outcomes.
Large food-processing plants will typically use more than 1,000,000 gallons of potable water per day. In the past, wastewater disposal costs were a small operating expense. More recently due to intensified enforcement of discharge regulations and escalating pre-treatment surcharges, many food-processing facilities are taking steps to recycle or treat their wastewaters before discharge.
The U.S. Geological Survey estimates thermoelectric generation accounted for 41 percent of all freshwater withdrawals in the Nation in 2005. Generators are looking to develop cost-effective approaches to using non-traditional sources of water to supplement or replace freshwater for cooling and other power plant needs. Examples of non-traditional waters include surface and underground mine pool water, coal-bed methane produced waters, and industrial and/or municipal wastewater.
During mineral extraction mine water can be pumped out to keep workings dry or to assist in extraction. As well the processing of minerals can be water intensive. This water can contain many contaminants and be highly acidic known as "acid rock drainage". Generally the water is treated and returned to underground aquifers or into an adjacent watercourse. It is expected new mine waste directives will introduce even stricter controls on the disposal of waste water from mines.