UPSTREAM OPERATIONS DRILLING WASTES REQUIRE EXTRA ATTENTION

Keith Rappold
Drilling Editor

The domestic drilling industry faces more uncertainty, as does the producing sector, on the exemption of drilling wastes from the Resource Conservation and Recovery Act (RCRA) reauthorization scheduled for next year.

Subtitle C of RCRA currently has exemptions for certain wastes associated with the exploration, development, and production of crude oil or natural gas.

These exemptions, however, do not cover every material or waste generated at the rig site. RCRA exempts some wastes common to drilling rigs and drilling sites. They are included in the production wastes shown in Table 1, p. 52, of this issue's article on production activities.

Many of these nonhazardous wastes are presently regulated under Subtitle D of RCRA. The removal of the Subtitle C exemption for these wastes will have a serious economic impact on the drilling industry. With day rates already at the breakeven point for a large number of contractors, many cannot afford the expense of hazardous waste disposal for these materials.

Subtitle C classification of these drilling wastes could result in a sharp drop in the number of wells drilled in the U.S. The Independent Petroleum Association of America estimated that about 40% fewer wells will be drilled if the exemption is removed.

The following list contains some of the nonexempt wastes found on drilling locations:

• Unused fracturing fluids or acids

• Painting wastes

• Oil and gas service company wastes, such as empty drums, drum rinsings, sandblast media, spent solvents, spilled chemicals, and waste acids

• Vacuum truck and drum rinsings from trucks and drums transporting or containing nonexempt waste

• Used lubrication oils

• Used hydraulic oils

• Waste solvents

• Sanitary wastes

• Drums, insulation, and miscellaneous wastes.

RCRA considers a waste as a substance that no longer fits its intended use and will be thrown away. A waste is considered hazardous if it is listed as a hazardous waste or if it has characteristics of a hazardous waste (D categories: ignitability, corrosivity, reactivity, and toxicity). RCRA lists wastes by chemical identity (P for acute hazardous wastes and U for toxic hazardous wastes) and by source of waste generation (F for hazardous wastes from nonspecific sources and K for hazardous wastes from specific sources).

The hazardous wastes with characteristics of ignitability include ignitable liquids with a flash point less than 140 F., ignitable compressed gas, ignitable reactives, and oxidizers. Corrosive characteristics cover aqueous solutions with pH less than or equal to 2.0 (acid) or greater than or equal to 12.5 (alkaline). Any liquid that corrodes a steel coupon (SAE 1020) at a rate greater than 0.250 in./year at test temperature of 130 F. is listed as a hazardous corrosive.

The characteristics of reactivity describe sulfide or cyanide-bearing wastes that produce harmful gases when exposed to OH condition less than 2.0 or greater than 12.5. Other reactive wastes include any materials that react violently with water and explosives.

Characteristics of toxicity vary depending on the type of chemical and concentration. There are eight heavy metal contaminants that are considered hazardous wastes. They are listed in Table 1 in the article on pipelining and gas processing operations, p. 46.

The Toxicity Characteristic Leaching Procedure (TCLP) is used for the determination of hazardous waste. TCLP covers waste handling and testing procedures for listed pesticides, organics, and metals.

All hazardous waste generators should develop some sort of waste management plan (OGJ, Apr. 22, pp. 8385). A simplified plan of hazardous waste identification for a generator site involves first determining which materials are solid waste Under RCRA. A driller should classify the solid wastes as exempt or nonexempt and then determine which nonexempt wastes are hazardous.

After identifying all hazardous wastes on location, the generator should calculate the amount of hazardous waste produced on the site. This systematic analysis will help the generator understand what functions on a drill site produce hazardous waste, with the ultimate goal of reduction in waste production.

GENERATOR NUMBERS

Under RCRA, a generator is any entity whose act or process produces hazardous waste. The EPA classifies hazardous waste generators in one of three categories: large quantity generators, small quantity generators, or conditionally exempt very small quantity generators (Table 1).

Each individual hazardous waste generation site receives classification according to the volume of waste generated and this classification can change over time as the produced volume of hazardous waste changes. Many rig sites can qualify for small quantity generator or conditionally exempt small quantity generator status after in initial thorough cleaning of the site and after implementation of a waste minimization program.

RCRA generator identification numbers track hazardous wastes from "cradle to grave." These identification numbers allow the EPA to follow hazardous wastes from the generator to the transporter to the disposal site. Thus, the EPA can trace the original waste generator and hold it liable for any future cleanup cost.

Sites classified as "conditionally exempt very small quantity generators" do not require generator identification numbers. However, the numbers are required for any site that produces more than 100 kg of hazardous waste or 1 kg of acutely hazardous waste.

Generator numbers apply to each specific site and not to a rig or company as a whole. Generator numbers are typically issued to fixed sites (drillsites, wells, yards, shops, etc.) and not to rigs. Only one party can obtain a generator number for a given site even though numerous contracted personnel and service companies may produce hazardous waste at the location.

Because generator identification numbers are site specific, the party with the largest or longest presence should obtain the number. Although a drilling contractor with its subcontractors may have the largest number of personnel and equipment on location, the operator maintains control of the site for the longest period and typically controls the drilling operation. Thus, the operator should obtain the generator identification number for a new well.

Although the operator typically acquires the generator number, some have required drilling contractors to obtain the number for drilling locations. During the drilling process, the rig produces a large portion of the waste on location. Drilling rig wastes include hydraulic fluids, used oils and filters, rigwash liquids, unused drilling mud and additives, drilled cuttings, and sanitary and hotel wastes. Clearly, some of these wastes result from normal rig operations, and others result from the drilled well (brine, excess mud, cuttings, etc.). Additionally, some of the common rig wastes fall into nonhazardous or exempt categories.

The generator identification numbers permanently stay with a specific site, and the number recipient remains responsible for all waste generated from the site. This could pose a problem for the drilling contractor that obtains a generator number for a drilling location. After rigging down and moving off, the contractor would then retain responsibility for wastes generated at a site, although it would no longer control operations at the site.

Normal production operations may leave various types of wastes around the well. Other rigs from subsequent workover and abandonment operations on the well may also generate hazardous wastes. All hazardous wastes from a particular site leave under the generator number for that site, and the original number holder retains responsibility.

One problem with the generator identification system stems from the issuance of one number to one party on one location. Each subcontractor on location must use that identification number to label any of its waste produced there. Others that use the generator number for hazardous wastes must keep additional records to prove which wastes belonged to them. Likewise, the party that holds the generator number has some responsibility for all hazardous wastes manifested with its number. Thus, it must police all hazardous waste generators on location to ensure full compliance.

WASTE MINIMIZATION

Most hazardous waste regulations discuss the steps and procedures a company must follow only after it generates or discovers a hazardous waste.

In addition to recognizing, classifying, and permitting wastes with the appropriate state and federal agencies, many companies have established proactive waste minimization programs for their drilling operations (OGJ, July 1, pp. 43-46).

As hazardous waste disposal costs increase (up to ten times the cost for nonhazardous waste disposal), economics play a greater role in the development of a waste minimization plan.

The waste minimization program should emphasize recycling and reuse, because a material is not a waste if it can be recycled. Another major focus of waste minimization programs is the segregation of hazardous from nonhazardous wastes. Under the EPA mixture rule, if any amount (no matter how small) of any listed hazardous waste mixes with any amount (no matter how large) of another material, the entire material becomes hazardous.

For example, if 1 bbl of a listed hazardous waste enters a reserve pit containing 10,000 bbl of nonhazardous fluid, the entire pit will become hazardous waste. These figures merely represent the magnitude of the situation.

A small hazardous waste problem becomes a large hazardous waste problem-this may even change the status of a site to large quantity generator. By minimizing liquid waste and carefully controlling the volumes of hazardous wastes on location, an operator can reduce disposal costs. Fig. 1 shows a lined pit system used to help contain and reduce reserve pit volume.

An indirect method of waste minimization involves due diligence surveys. Soil and water testing on sites before moving in a rig may find preexisting problems. The technology and standards acceptable decades ago may no longer be acceptable. If a previous operator or industrial facility left hazardous materials in pits or landfarmed on location, the new operator may become liable for expensive cleanup unless it can prove the origin of the wastes-a difficult task.

The EPA considers the following as potential responsible parties if pollution is found on a drilling site: past and present owners or operators of the site, generators of hazardous substances found at the site, and transporters of hazardous substances to the site.

WASTE HANDLING

If hazardous wastes will be stored in drums or containers on site for even a brief period, the containers should undergo regular inspection. Each drum or container should have a label indicating the date the material was generated and the words "hazardous waste" prominently displayed.

The mess shown on the location in Fig. 2 consists of half-used drilling mud sacks, oil waste on the ground, and damaged drums. A lack of regular inspections allowed this mud storage facility to degenerate into a problem.

Good housekeeping practices on site help reduce the volume of hazardous waste generated. Fig. 3 shows a rig worker carefully storing spent sacks of mud additives. Careful separation of hazardous waste from other waste prevented contamination of nonhazardous materials.

Crew members on location should exercise extreme caution not to mix hazardous spent cleaning solvents with other wastes. Unknown chemical mixtures may react violently, producing harmful or more dangerous chemicals. At a minimum, such bad practices increase the total volume of hazardous waste for disposal.

Another good handling practice is to keep the hazardous waste drums closed. Containers should have labels indicating whether the waste inside is ignitable, corrosive, toxic, or reactive. Containers should be placed away from activity on the rig site and preferably surrounded with ring levees to separate and contain rainwater runoff.

The RCRA regulations have made a distinction between waste accumulation and waste storage. Accumulation begins when a generator first places hazardous waste into a receptacle; storage is merely long-term accumulation. Any party that stores hazardous waste must obtain an RCRA permit; drilling operations should avoid such situations because the process is complex and may involve an expensive cleanup bill.

It behooves a generator to haul off accumulations of hazardous waste as often as practicable. This eliminates the chance of becoming a storage facility and can help maintain the lowest possible generator status.

The Satellite Accumulation Rule states that the accumulation time table does not begin until the hazardous waste container is full. Most land drilling rigs can fall under this rule, provided they meet the following stipulations:

• Maximum container size shall not exceed 55 gal.

• The generator must maintain control of the container.

• The container must remain at the point of waste generation.

• The container must have proper labels, including the words "hazardous waste."

Waste must be classified on site before it is transported. Identification and classification of the waste ma indicate that the waste is nonhazardous, and therefore not subject to RCRA. A little planning can prevent costly and perhaps unnecessary disposal.

Hazardous waste transporters must obtain an EPA identification number, manifest the waste and retain copies for a minimum of 3 years, and take immediate action in the event of a spill. The generator has the responsibility of verifying the transporter's identification number, insurance, and licenses. Additionally, each state the generator ships waste to and from may require separate manifest forms.

USED OIL

In September, the EPA published a proposed rulemaking to change regulations on the hazardous waste management system and the disposition of used oil. The EPA is considering whether hazardous waste evaluation and listing of used oil at the point of generation is appropriate. The International Association of Drilling Contractors (IADC) believes that used oil generated from diesel-powered heavy equipment used on drilling rigs is generally nonhazardous.

The Maximum Contaminant Level (MCL) standards under the Safe Drinking Water Act should not replace the Toxicity Characteristic Leaching Procedure (TCLP) tests currently used for hazardous waste determination. The MCL tests apply to drinking water and are too severe for industrial used oil. The use of the MCL standards on used oil would result in excessive costs to the drilling industry.

Additionally, the EPA has considered having used oil undergo a TCLP test each time the oil would be disposed. TCLP tests for used oil can cost approximately $1,000-1,500. Mandatory testing of all used oil and filters will cause expenses to increase. Many drilling contractors already run periodic spot tests of their used oil.

Other proposals for used oil include testing for halogen content and hazardous waste characteristics. The generator would have to carry out these tests prior to disposal of the used oil. A onetime demonstration test of the used oil at the source can demonstrate if the oil is hazardous. The test results could be kept with the individual components at the rig site for inspection by EPA officials.

The EPA has also proposed to exempt nonhazardous waste waters contaminated with very small quantities of listed used oil from RCRA.

This rule will help the drilling industry, but the amount of contamination is subjective. Any amount not quantitatively specified leaves the door open for future problems. Another proposal would require a generator or recycler to drain and crush used oil filters, thereby granting the filters exemption from regulation as hazardous waste. This exemption would then classify the crushed filters as solid waste.

The EPA has considered the feasibility of a total ban on the disposal of all used oil on land. According to the IADC, nonhazardous used oil should be treated as all other nonhazardous waste is treated-not regulated. The only viable disposal option with a land ban in place would be incineration (approximately $300-600/bbl). Deep well injection, bioremediation, solidification, and landfill disposal remain the other viable options.

BIBLIOGRAPHY

1. Godec, M.L., and Bigiargigi, K., "Economic Effects of Environmental Regulations on Finding and Developing Crude Oil in the U.S.," Paper 20619 presented at the SPE Annual Technical Conference and Exhibition, New Orleans, Sept. 23-26, 1990.

2. API Environmental Guidance Document, First Edition, Jan. 15, 1989.

3. Grove, M., "Management and Disposition of Oilfield Waste," IADC Hazardous Waste Seminar, New Orleans, Nov. 4, 1991.

4. Wojtanowicz, A.K., "Environmental Control Potential of Drilling Engineering: An Overview of Existing Technologies," Paper 21954 presented at the SPE/IADC Drilling Conference, Amsterdam, The Netherlands, Mar. 11-14, 1991.

5. IADC Recommended Practices for RCRA Compliance, First Edition, April 1991.

Copyright 1991 Oil & Gas Journal. All Rights Reserved.