PIPELINES AND GAS PROCESSING PIPELINERS AND GAS PROCESSORS TARGET EVEN CLEANER OPERATIONS

Warren R. True
Pipeline/Gas Processing Editor

With the recent passage of amendments to the federal Clean Air Act (OGJ, Oct. 29, 1990, p. 18) and the reauthorization next year of the Resource Conservation and Recovery Act, pipelines and gas processors are looking at more ways to tighten operations and avoid polluting surface water or air.

Some companies are not waiting for the final rules but are taking actions which anticipate tougher standards.

RCRA RULES

Understanding what pipelines and gas processors are doing first requires an understanding of what they have been required to do and of what changes to the CAA and RCRA may mean. In that regard, it is impossible to underestimate the dominant role played by RCRA since its initial passage 25 years ago.

RCRA fulfills three basic functions:

Defines a hazardous waste
Establishes a U.S. Environmental Protection Agency (EPA) identification (ID) number for each generator of hazardous waste
Requires the manifesting of each shipment of hazardous waste that leaves the site of its generation. This latter aspect is the key in RCRA's hazardous waste tracking system.

Under RCRA, a "solid waste" is any material discarded or intended to be discarded. Solid wastes may be solid, semi-solid, liquid, or contain gases.

The physical form of the waste bears slight relationship to its being a solid waste. That's an important distinction for pipeline and crude and product storage operations in which watercontacting hydrocarbons are ever-present.

Further, RCRA designates a solid waste hazardous if it is specifically listed as a hazardous waste (there are more than 400) or if it exhibits one or more of the characteristics of hazardous wastes.

These characteristics are:

Ignitibility
Corrosivity
Reactivity
Toxicity.

The passage in 1984 of amendments to RCRA, known as the Hazardous and Solid Waste amendments, called for an improved leaching procedure for defining the toxicity characteristics. As a result, the toxicity characteristics leaching procedure (TCLP) replaced the former extraction procedure (EP) toxicity test in late 1990.

At the same time, EPA added 25 additional organic constituents to the toxicity characteristic list which TCLP had identified. Table 1 shows the limits allowed for substances that are found present in the leachate of a particular tested waste.

For pipelines and gas processors, the most important one on that list is the maximum allowable for benzene in any given leachate: 0.5 PPM.

An important aspect in EPA's RCRA regulations has become known as the "mixture rule." Simply stated, the rule provides that the mixing of any listed hazardous waste with a nonhazardous waste renders the entire mixture hazardous.

For example, discarding a half-empty container of solvent, a listed hazardous waste, in an otherwise exempt reserve pit would cause the pit contents to become a hazardous waste.1 The result would be an expensive closing of the reserve pit under RCRA hazardous waste regulations.1

Additionally, unused commercial products should not be disposed of with oil field wastes. All reasonable efforts should be made completely to use commercial products, return them to their vendors if not fully used, or segregate them from other wastes for management and disposal.

Another important part of RCRA-and relevant to pipelines and gas processors as the act comes up for reauthorization-are the substances excluded from the hazardous-waste designation.

Exempt, among others, are substances generated in oil and natural-gas exploration drilling. Produced water, therefore, when knocked out in a gas plant's inlet-gas separator is not classified as a hazardous waste.

PCB EFFORTS

For more than 10 years now, the thorniest issue for natural-gas pipelines has been the presence of polychlorinated biphenyls (PCBS) in and along their systems. Dealing with PCBS, however, falls under coverage of the Toxic Substances Control Act (TSCA); they are not a listed hazardous waste under RCRA.

Virtually every gas pipeline in the U.S. has found PCBs to some extent in its system. And all have instituted some program to monitor and clean up any occurrence.

The Gas Research Institute (GRI) initiated a research program in 1989 to address technical issues associated with proper management of PCB residue from past gas operations.

Initial activities focused on measurement and statistical analysis of data associated with PCB contamination of transmission pipelines and a review of PCB management technology for various media of interest to the industry during assessment and remediation programs, including condensate, soil, pipelines, and facility surfaces.

Work in 1991-92 is focusing on specific technical issues identified by the gas industry as critical to PCB-management decisions and environmental assessments.

Active project work areas include developing information on physical properties and analytical methods for PCB-condensate mixtures; the soil-water partitioning behavior of these mixtures; and a formal evaluation of the potential range of risks associated with typical pipeline operations or abandonment in place.

Future work, says GRI, will build on the findings of these key scientific and technical areas and will focus on understanding the migration of PCBs in pipeline systems and evaluating and developing treatment, control, and innovative analytical technologies for PCBs in various media.2

Texas Eastern Gas Pipeline Co., Houston, conducted a 2-month test this summer on the use of PCB-eating microorganisms. Late last month, these organisms were injected into a 40 x 12 ft test area of PCB-contaminated soil near Texas Eastern's St. Francisville, La., compressor station.

The organisms were developed at Louisiana State University specifically to address PCB contamination in soils.

Texas Eastern says that the overall test will require about 6 months and will continue so long as the ground temperature remains warmer than 50 F. Should the temperature cool to less than that level, the test will be suspended until next spring.

CAA

Although RCRA appears to be the most widely applicable environmental statute for pipeline and gas-processing operations, implications of amendments passed last year to the Clean Air Act cannot be overlooked.

In terms of air quality, the substances of primary concern found around gas processing and pipeline operations include carbon dioxide, hydrogen sulfide, and mercaptan sulfur. These elements are often present in gas streams flowing through gathering systems and entering gas plants.

Additionally, pipelines and gas processors must be concerned with sources of nitrous oxide (NOx) and carbon monoxide (CO) emissions from compressor and pump engines as well as from any other power-generating source which uses hydrocarbon fuel.

These sources, as well as any fugitive emissions around seals, at pumps, compressors, meters, or storage tanks, for example, will be of concern for benzene content.

Todd Williams and Kristen Woody of Roy F. Weston Inc., a nation-wide environmental engineering consulting firm, have stated that the most significant aspect of the amended CAA relates to benzene.3

The company recommends that pipelines start programs to calculate benzene emissions not only from dehydrators but for all potential emissions at each facility.

Amendments to CAA address the subject of toxic air pollutants by listing 189 chemicals to be regulated. Within 10 years, the EPA must issue standards for "maximum achievable control technology" (MACT) for all sources of these 189 chemicals.

COMPANIES' ACTIONS

In the past, some pipelines and gas processors may have adopted an attitude of first opposing any regulations, then of delaying any actions until final regulations were formulated.

But, as one environmental director at a major gas-transmission company said, nearly everyone who has come into the industry in recent years is an environmentalist.

Industry associations for petroleum and natural-gas pipelines and for gas processors are working closely with EPA officials to fashion regulations that effectively and realistically address, for example, the timetables set out in CAA.

MANUALS, AUDITING PROGRAMS

Tenneco Gas' Environmental Director Jay A. Greenwalt says that Tenneco Gas early obtained hazardous-waste generator ID numbers for each facility which might later be tagged as a generator. "We did this even though some of the facilities might not qualify or at least be very small generators," he says.

The company formalized much of the guidance for procedures at facilities in 1984 with an Environmental Compliance Manual issued for each facility. The manual has been updated with specific memoranda since that time. "But," says Greenwalt, "basics so far as our handling of wastes have remained pretty much the same."

The manual addresses not only defined wastes under RCRA but all potential concerns. It's basically a procedures book for field locations, Greenwalt says. Tenneco Gas is preparing a new manual to be issued in early 1992. The manual, says Kevin D. Romine, Tenneco Gas' senior environmental scientist, addresses all environmental legislation at federal, state, and local levels.

Another company that has set out in a readable, concise manual its environmental goals, policies, and procedures is Transco Energy Co.

Transco's 11-page document covers permits, spill prevention and reporting, management of wastes, underground storage tanks, and PCBS. Policies and specific procedures are set forth firmly to support the manual's rationale:

"The greatest protection against [accidents, fires, and pollution] results when environmentally aware and safety conscious employees work in an environment designed to meet, and in many cases exceed, regulatory and voluntary standards."

State regulations, says Tenneco Gas' Greenwalt, have become more and more stringent over the years, especially for water issues. Romine cites as particularly aggressive the states of Kentucky, Pennsylvania, and New York.

"From a natural-gas pipeline standpoint," says Romine, "we don't generate a lot of listed hazardous waste. Most of our wastes are 'characteristic' under TCLP." Typical wastes, he says, are pipeline condensates from drips downstream of compressors, solvents used to clean metal parts, and waste oils.

In 1990, Tennessee Gas generated approximately 125,000 gal/year of waste oil for 13 stations.

But Romine estimates that the typical yearly waste-oil production is about 20,000 gal or more. Variations depend on how much maintenance is performed on engines, how much they are run, and how often manufacturers of a particular oil recommend draining.

"We're not calling our waste oil a hazardous waste," says Greenwalt. "We typically recycle it."

RCRA specifically exempts "used oil" being recycled for product value. This accounts for by far the bulk of waste oil generated by pipelines and gas processors.

All companies contacted for this report indicated they sell their waste oils to recyclers for rerefining into a product.

Waste oil recyled for its energy value, that is, burned as a fuel, requires notification of EPA and is regulated to ensure proper operation of the energy-recovery facility.

Land application of used oil, long a popular disposal method, is now closely regulated. Any used oil that is determined hazardous by TCLP may not be disposed of by dumping.

Land dumping in fact is generally shunned by companies which see them posing potential future problems.

Because RCRA makes Tenneco Gas and any other generator of hazardous waste responsible for that substance "cradle to grave," the company is typical of many pipelines and gas processors in its efforts to ensure that contractors who pick up, transport, and dispose of wastes from its operations are reliable and sound firms.

This is accomplished with Tenneco Gas' four point auditing program of each handler of waste material who contracts with the company. Most companies, Transco included, also have such auditing programs; Tenneco's is typical.

The four points are a financial review of the company, a site audit of the company's handling and disposal facilities, inquiries of state and federal regulatory agency personnel who have also inspected the company's site, and a close review by Tenneco Gas' legal department of the contract to be signed.

Inquiries of the agencies about a company include:

Under what kinds of permits does it operate?
When violations are cited, how quickly and completely does the company respond?
Is the company currently under any enforcement action or is there any pending enforcement?
Has the company ever had spills which resulted in groundwater or soil contamination?
When was the company's site last inspected? How often is it inspected and are the inspections announced?

Fig. 1 shows a typical "Approval Tracking Form" employed by Tenneco Gas for each waste-service company. This form follows the entire auditing process and is signed by a corporate vice-president only when completed and signed by the division manager and the director of environmental.

"Requiring a vice-president's signature is a way of emphasizing environmental concerns well up the corporate structure," says Romine.

In the past, environmental groups have noted a correlation between a company's efforts and the level of its corporate command chain involved in those efforts. The higher the level, the more complete and successful the efforts.

WATER

Disposition of used oil is a common problem for any industrial concern. Water is also present in pipeline and gas-processing operations and for some types of companies presents the most significant disposal problems.

Pipelines generate potential hazardous waste in water by hydrotesting segments of line and thereby picking up hydrocarbons in the water. Petroleum liquid pipeline companies which are also involved in storage operations must deal with hydrocarbon-bearing water from tank bottoms.

Texas Eastern Products Pipeline Co. Vice-President of Operations O. H. Cunningham says that for his company's handling of waste water, the impact of the TCLP has been enormous.

"Waste water is by far our largest waste stream," he says.

What had generally been nonhazardous waste water prior to the benzene-level criterion of TCLP is now generally hazardous, Cunningham says. As stated earlier, 0.5 ppm benzene in the leachate of a substance tested under the TCLP makes the substance hazardous (Table 1).

Water is generated from at least three sources on Texas Eastern's system: flushing of tank storage, tank bottoms, and hydrostatic testing of pipelines. A small amount of water comes into any storage tank if a product is warm when it arrives then cools to drop out water.

Cunningham states that disposal methods used prior to TCLP have been revised or in some cases discarded. "Where we have on site treatment of waste water, we are continuing to do that.

"Where we were hauling water for treatment to, say, a permitted municipal waste water treatment facility such as near Seymour, Ind., we've had to make changes if that facility was not permitted for hazardous waste," Cunningham states.

Texas Eastern is currently searching for publicly owned works along its system authorized to take hazardous waste. But in a few instances, it has been less expensive to incinerate the water.

The company has installed a biological water treatment unit at its Beaumont, Tex., tank storage facility. That program may be a signal for the future for other companies.4

Anticipating in 1987 that tank-bottoms water would eventually become a regulated waste, the company carried out during 1988-89 a pilot plant study of the use of a conventional activated sludge process for treatment of hazardous waste water.

The study indicated substantial success in reducing hazardous components in waste water to acceptable levels. In 1990, a full-scale water treatment tank was installed based on an inventory of 40,000 bbl of tank water bottoms needing disposal, a variation in dissolved organic concentrations of free-phase gasoline, diesel fuel, and kerosine, and acceptable treatment rates of 5-20 gpm on a 24-hr basis.

Final process design included an oil-water separator to prevent free-phase product from entering the biological reactor, a multichambered aerated biological reactor capable of programmable modes of operation, a gravity clarifier with mechanical rake and sludge thickener (Fig. 2), aerobic digester, and clarifier overflow clearwell to provide a reservoir of clean water for plant cleaning and filter backwash.

EMISSIONS, SLUDGE, AND DRIPS

On the subject of benzene in vapors emitted from tanks, Cunningham noted that the final regulations under CAA amendments have not been formulated. Texas Eastern, he says, has no current plans now to install sophisticated vapor-recovery units (VRUs) or refrigerated vent condensers to capture fugitive emissions from floating roof tanks.

Amoco Pipeline is actively studying the subject of potentially hazardous emissions on its pipelines and storage facilities.

Amoco Oil Co.'s Director of Environmental Services Sandy Medley says that the company is beginning a program to discover emissions. It will survey facilities to determine emission levels using API Method 42 to calculate what and how much is going into the air around storage areas.

By late 1992, she said, vapor-recovery units will be required at all facilities.

For pipelines such as Amoco's and Texas Eastern's, another source of potentially hazardous waste occurs in the sludge resulting from pipeline pigging operations.

Scraper and cleaning pigs deposit hydrocarbon-bearing materials at pig receipt sites. This material must undergo TCLP and, depending on what has been transported, will likely reveal the presence of hazardous levels of benzene as well as listed metals.

It is then handled as any other hazardous material. Medley indicated that efforts are generally made to prevent this material from coming into contact with the soil.

Similarly, condensate drips downstream of compressor stations are captured, tested under TCLP, and handled accordingly.

Enron Gas Pipeline Co.'s Director of Environmental Affairs Kevin McGlynn lumped the handling of condensate with other liquid by-products of gas pipeline operations, noting that efforts are made to prevent condensate from drips or blow by's from reaching the soil.

Condensates are segregated as a waste and dealt with as hazardous.

GAS PROCESSORS' CONCERNS

Much of what has been said here about substances of concern for pipelines applies to gas processors as well. Waste lubricating oil from machinery, condensate drips, solvents, and waste water are present in a gas plant.

The Gas Processors Association has established a task force to prepare guidelines and make recommendations for "environmentally sound management" of solid waste which results from plant operations.

Michael Ford, an environmental scientist with Phillips Petroleum Co., Bartlesville, says that Phillips' gas plant operations are typical of most in the wastes they generate.

He points out that spent molecular-sieve catalyst from gas-dehydration operations constitutes a waste that is typically nonhazardous and specifically exempt by RCRA.

Other dehydration operations, typically glycol based, as well as sulfur-removal activities, generate little waste. The glycol or amines used are regenerated and returned to their towers.

What waste water is generated from gas-plant activities is handled as other companies handle it: tested by TCLP, classified, and disposed of accordingly. Water from cooling-tower operations and produced water entrained with the gas stream are waste streams specifically exempt under RCRA.

Ford points out that cooling-tower technology has improved in recent years to the extent that less waste water is now generated.

To address the problem of hydrocarbons in waste water, Ford said that some Phillips gas-processing operations are separating the water from the hydrocarbons then burning off the hydrocarbons (Fig. 3).

Alternatively, the water-hydrocarbon stream is routed back to the plant's gas-inlet scrubber where the water drops out and the hydrocarbons are sent to a slop oil tank to form part of a product stream sold by the plant.

Gas plants also have much the same emission concerns as pipelines. Internal-combustion engines in Phillips' plants are typically fired by sweetened natural gas with consequent emissions of NOx, CO, and C3+.

Wherever Phillips must obtain an air-quality permit for such engines, the company is installing catalytic converters (the "best available control technology"-BACT) on these engines to reduce potential polluting emissions.

Ford notes that many recent permitting procedures require operators periodically to check sources of fugitive emissions. Phillips has installed such an inspection program to reduce emissions at valves, flanges, compressor seals, and other plant components.

Potential emissions from acid-gas treating operations are also a potential source of air-quality degradation.

Ford states that existing federal New Source Performance Standards (NSPS) imply that if the acid gas in an inlet stream contains less than 2 long tons/day of sulfur, the separated H2S and CO2 may be routed to a flare stack.

But economics and technical feasibility for new sulfur-recovery technology, which must be reviewed before an operator can obtain a new permit, may have effectively lowered that ceiling to one-half long ton/day, he says.

Finally, Phillips has installed a company-wide program to reduce the amounts and types of waste generated at its facilities. Such "waste minimization" programs are being set up throughout the pipeline and gas-processing industries.

REFERENCES

yed, Talib, and Shapiro, Robert A., "Waste Management-Disposal Technology and Regulatory Control in the 1990's," 70th Annual GPA Convention, Mar. 11-12, 1991, San Antonio.
Frank, James R., and John P. Woodyard, "Examination of PCB Management Technology Issues," Institute of Gas Technology Conference, Chicago, July 16, 1991.
Williams, Todd M., and Woody, Kristen J., "Environmental Issues Facing the Pipeline Industry in the 1990's," Petro-Safe '91, Houston, Feb. 6-8, 1991.
Green, Edward Lamaer, and Shevlin, Patrick J., "Pilot Plant Treatment of Petroleum Terminal Tank Water Bottoms using Conventional Activated Sludge Process," Marketing Terminal Environmental Task Force (API) meeting, San Francisco, Sept. 13, 1990.