Technology Descriptions

Separation of Mud from Cuttings

Solidification and Stabilization

Drilling Practices That Minimize

Generation of Drilling Wastes

Using Muds and Additives with

Lower Environmental Impacts

Beneficial Reuse of Drilling Wastes

Onsite Burial (Pits, Landfills)

Land Application

Bioremediation

Discharge to Ocean

Commercial Disposal Facilities

Slurry Injection of Drilling Wastes

Disposal in Salt Caverns

Thermal Treatment Technologies

Federal & State Regulations

Technology Identification

Home » Te chnology De scriptions » Land Application

Fact Sheet - Land Application

The objective of applying drilling wastes to the land is to allow the soil's naturally

occurring microbial population to metabolize, transform, and assimilate waste

constituents in place. Land application is a form of bioremediation, and is

important enough to be described in its own fact sheet; other forms of

bioremediation are described in a separate fact sheet.

Several terms are used to describe this waste management approach, which can

be considered both treatment and disposal. In general, land farming refers to the

repeated application of wastes to the soil surface, whereas land spreading and

land treatment are often used interchangeably to describe the one-time application

of wastes to the soil surface. Some practitioners do not follow the same

terminology convention, and may interchange all three terms. Readers should

focus on the technologies rather than on the specific names given to each

process.

Optimal land application techniques balance the additions of waste against a

soil's capacity to assimilate the waste constituents without destroying soil

integrity, creating subsurface soil contamination problems, or causing other

adverse environmental impacts.

Land Farming

The exploration and production (E&P) industry has used land farming to treat oily

petroleum industry wastes for years. Land farming is the controlled and repeated

application of wastes to the soil surface, using microorganisms in the soil to

naturally biodegrade hydrocarbon constituents, dilute and attenuate metals, and

transform and assimilate waste constituents.

Land farming can be a relatively low-cost drilling waste management approach.

Some studies indicate that land farming does not adversely affect soils and may

even benefit certain sandy soils by increasing their water-retaining capacity and

reducing fertilizer losses. Inorganic compounds and metals are diluted in the soil,

and may also be incorporated into the matrix (through chelation, exchange

reactions, covalent bonding, or other processes) or may become less soluble

through oxidation, precipitation, and pH effects. The attenuation of heavy metals

(or the taking up of metals by plants) can depend on clay content and cationexchange capacity.

Optimizing Land Farm Operations: The addition of water, nutrients, and other

amendments (e.g., manure, straw) can increase the biological activity and

aeration of the soil, thereby preventing the development of conditions that might

promote leaching and mobilization of inorganic contaminants. During periods of

extended dry conditions, moisture control may also be needed to minimize dust.

Periodic tillage of the mixture (to increase aeration) and nutrient additions to the

waste-soil mixture can enhance aerobic biodegradation of hydrocarbons. After

applying the wastes, hydrocarbon concentrations are monitored to measure

progress and determine the need for enhancing the biodegradation processes.

Application rates should be controlled to minimize the potential for runoff.

Pretreating the wastes by composting and activating aerobic biodegradation by

regular turning (windrows) or by forced ventilation (biopiles) can reduce the

amount of acreage required for land farming (Morillon et al. 2002).

Drilling Waste Land Farm Example: In 1995, HS Resources, an oil and gas company

operating in Colorado, obtained a permit for a noncommercial land farm to treat

and recycle the company's nonhazardous oil field wastes, including drilling muds.
At the land farm, wastes mixed with soil contaminated with hydrocarbons from

other facilities are spread in a layer one foot thick or less. Natural bacterial action

is enhanced through occasional addition of commercial fertilizers, monthly tilling

(to add oxygen), and watering (to maintain 10-15% moisture content). Treatment

is considered complete when hydrocarbon levels reach concentrations specified by

regulatory agencies; not all agencies employ the same acceptability standards.

Water and soil are monitored periodically to confirm that no adverse soil or

groundwater impacts have occurred, and records of the source and disposition of

the remediated soil are maintained. Estimated treatment costs, which include

transportation, spreading, amendments, and monitoring, are about $4-5 per cubic

yard. When the treated material is recycled as backfill, net costs are about $1 per

cubic yard. Capital costs (not included in the treatment cost estimates) were

recovered within the first eight months of operation (Cole and Mark 2000).

Implementation Considerations: Advantages of land farming include its simplicity

and low capital cost, the ability to apply multiple waste loadings to the same

parcel of land, and the potential to improve soil conditions. Concerns associated

with land farming are its high maintenance costs (e.g., for periodic land tilling,

fertilizer); potentially large land requirements; and required analysis, testing,

demonstration, and monitoring. Elevated concentrations of hydrocarbons in

drilling wastes can limit the application rate of a waste on a site.

Wastes containing salt must also be carefully applied to soil. Salt, unlike

hydrocarbons, cannot biodegrade but may accumulate in soils, which have a

limited capacity to accept salts. If salt levels become too high, the soils may be

damaged and treatment of hydrocarbons can be inhibited. Salts are soluble in

water and can be managed. Salt management is part of prudent operation of a

land farm.

Another concern with land farming is that while lower molecular-weight petroleum

compounds biodegrade efficiently, higher molecular-weight compounds

biodegrade more slowly. This means that repeated applications can lead to

accumulation of high molecular weight compounds. At high concentrations, these

recalcitrant constituents can increase soil-water repellency, affect plant grow th,

reduce the ability of the soil to support a diverse community of organisms, and

render the land farm no longer useable without treatment or amendment

(Callahan et al. 2002). Recent studies have supported the idea that field-scale

additions of earthworms with selected organic amendments may hasten the longterm recovery of conventionally treated petroleum contaminated soil. The

burrowing and feeding activities of earthworms create space and allow food

resources to become available to other soil organisms that would be unable to

survive otherwise. The use of earthworms in Europe has improved the biological

quality of soils of some large-scale land-reclamation projects.

When considering land farming as a waste management option, several items

should be considered. These include site topography, site hydrology, neighboring

land use, and the physical (texture and bulk density) and chemical composition of

the waste and the resulting waste-soil mixture. Wastes that contain large

amounts of oil and various additives may have diverse effects on parts of the food

chain. Constituents of particular concern include pH, nitrogen (total mass), major

soluble ions (Ca, Mg, Na, Cl), electrical conductivity, total metals, extractable

organic halogens, oil content, and hydrocarbons. Oil-based muds typically utilize

an emulsified phase of 20 to 35 percent by weight CaCl2 brine. This salt can be a

problem in some areas, such as some parts of Canada, the mid-continent, and the

Rocky Mountains. For this reason, alternative mud systems have emerged that

use an environmentally preferred beneficial salt, such as calcium nitrate or

potassium sulfate as the emulsified internal water phase.

Wastes that contain significant levels of biologically available heavy metals and

persistent toxic compounds are not good candidates for land farming, as these

substances can accumulate in the soil to a level that renders the land unfit for

further use (E&P Forum 1993). (Site monitoring can help ensure such accumulation

does not occur.) Land farms may require permits or other approvals from

regulatory agencies, and, depending on soil conditions, some land farms may

require liners and/or groundwater monitoring wells.

Land Treatment

In land treatment (also known as land spreading), the processes are similar to

those in land farming, where natural soil processes are used to biodegrade the

organic constituents in the waste. However, in land treatment, a one-time

application of the waste is made to a parcel of land. The objective is to dispose of
the waste in a manner that preserves the subsoil's chemical, biological, and

physical properties by limiting the accumulation of contaminants and protecting

the quality of surface and groundwater. The land spreading area is determined on

the basis of a calculated loading rate that considers the absolute salt

concentration, hydrocarbon concentration, metals concentration, and pH level

after mixing with the soil. The drilling waste is spread on the land and

incorporated into the upper soil zone (typically upper 6-8 inches of soil) to

enhance hydrocarbon volatization and biodegradation. The land is managed so

that the soil system can degrade, transport, and assimilate the waste

constituents. Each land treatment site is generally used only once.

Optimizing Land Treatment Operations: Addition of water, nutrients, and other

amendments (e.g., manure, straw) can increase the biological activity and

aeration of the soil and prevent the development of conditions that might

promote leaching and mobilization of inorganic contaminants. During periods of

extended dry conditions, moisture control may also be needed to minimize dust.

Periodic tillage of the mixture (to increase aeration) and nutrient additions to the

waste soil mixture can enhance aerobic biodegradation of hydrocarbons, although

in practice not all land treatment projects include repeated tilling. After applying

the wastes, hydrocarbon concentrations may be monitored to measure progress

and determine the need for enhancing the biodegradation processes.

Implementation Considerations: Because land spreading sites receive only a single

application of waste, the potential for accumulation of waste components in the

soil is reduced (as compared with land farming, where waste is applied

repeatedly). Although liners and monitoring of leachate are typically not required

at land treatment sites, site topography, hydrology, and the physical and chemical

composition of the waste and resultant waste-soil mixture should be assessed,

with waste application rates controlled to minimize the possibility of runoff.

Experiments conducted in France showed that after spreading oil-based mud

cuttings on farmland, followed by plowing, tilling, and fertilizing, approximately

10% of the initial quantity of the oil remained in the soil. Phytotoxic effects on

seed germination and sprouting were not observed, but corn and wheat crop

yields decreased by 10% (Smith et al. 1999). Yields of other crops were not

affected. The percentage of hydrocarbon reduction and crop yield performance will

vary from site to site depending on many factors (e.g., length of time after

application, type of hydrocarbon, soil chemistry, temperature).

Land spreading costs are typically $2.50 to $3.00 per barrel of water-based

drilling fluids not contaminated with oil, and they could be higher for oily wastes

containing salts (Bansal and Sugiarto 1999). Costs also depend on sampling and

analytical requirements.

Advantages of land spreading are the low treatment cost and the possibility that

the approach could improve soil characteristics. Land spreading is most effectively

used for drilling wastes that have low levels of hydrocarbons and salts. Potential

concerns include the need for large land areas; the relatively slow degradation

process (the rate of biodegradation is controlled by the inherent biodegradation

properties of the waste constituents, soil temperature, soil-water content, and

contact between the microorganisms and the wastes); and the need for analyses,

tests, and demonstrations. Also, high concentrations of soluble salts or metals

can limit the use of land spreading.

When evaluating land spreading as a drilling waste management option, several

items should be considered. These include area-wide topographical and geological

features; current and likely future activities around the disposal site;

hydrogeologic data (location, size, and direction of flow for existing surface water

bodies and fresh or useable aquifers); natural or existing drainage patterns;

nearby environmentally sensitive features such as wetlands, urban areas,

historical or archeological sites, and protected habitats; the presence of

endangered species; and potential air quality impacts. In addition, historical

rainfall distribution data should be reviewed to establish moisture requirements

for land spreading and predict net evaporation rates. Devices needed to control

water flow into, onto, or from facility systems should be identified. Wastes should

be characterized during the evaluation; drilling wastes with high levels of

hydrocarbons and salts may not be appropriate for land spreading.

References

Bansal, K.M., and Sugiarto, 1999, "Exploration and Production Operations - Waste

Management A Comparative Overview: U.S. and Indonesia Cases," SPE 54345,
SPE Asia Pacific Oil and Gas Conference, Jakarta, Indonesia, April 20-22.

Callahan, M.A., A.J. Stewart, C. Alarcon, and S.J. McMillen, 2002, "Effects of

Earthworm (Eisenia Fetida) and Wheat (Triticum Aestivum) Straw Additions on

Selected Properties of Petroleum-Contaminated Soils," Environmental Toxicology

and Chemistry, Vol. 21, No. 8, pp. 1658-1663.

Cole, E., and S. Mark, 2000, "E&P Waste: Manage It Cost Effectively through Land

Farming," World Oil, August Vol. 221, No. 8.

E&P Forum, 1993, "Exploration and Production (E&P) Waste Management

Guidelines," Report No. 2.58/196, September.

Morillon, A., J.F. Vidalie, U.S. Hamzah, S. Suripno, and E.K. Hadinoto, 2002, "Drilling

and Waste Management", SPE 73931, presented at the SPE International

Conference on Health, Safety, and the Environment in Oil and Gas Exploration and

Production, March 20-22.

Smith, M., A. Manning, and M. Lang, 1999, "Research on the Re-use of Drill

Cuttings Onshore," November 11.

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Technology Identification

Home » Technology Identification

Drilling Waste Management Technology

Identification Module

The Technology Identification Module is an interactive tool for identifying

appropriate drilling waste management strategies for a given well location and

circumstances.

The Technology Identification Module follows the philosophy of a waste

management hierarchy. Waste management options with the lowest

environmental impacts are encouraged ahead of those with more significant

environmental impacts. The Technology Identification Module helps identify waste

management options, but users should also consider their own site-specific costs

and waste volumes.

How it Works

Users will be asked to answer a series of questions about the location of the well

site, physical features of the site that may allow or inhibit the use of various

options, whether the regulatory agency with jurisdiction allows or prohibits

particular options, and whether cost or the user's company policy would preclude

any options. Nearly all questions are set up for only "yes" or "no" responses.

Depending on how the initial questions are answered, users will face from 15 to

35 total questions. Some of these can be answered immediately, while others

may require some additional investigation of other portions of this web site or

external information. Suitable options will be identified as users complete the

questions, and users will be able to print out a summary of suitable options when

the process is completed.

Click here to begin

First-time users are encouraged to run quickly through the list of questions and

provide sample answers to see the types of information that are needed to

complete the questions. Then they can return to answer questions more carefully

and to explore multiple options.

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Federal & State Regulations

Federal Regulations: Environmental

Protection Agency

Federal Regulations: Bureau of

Land Management

Federal Regulations: Bureau of

Ocean Energy Management,

Regulation and Enforcement

State Regulations

Technology Identification

Home » Federal and State Regulations

Federal & State Regulations

Drilling waste management practices are subject to all applicable federal and

state regulatory requirements. The regulatory module of the Drilling Waste

Management Information System (DWMIS) is designed to offer a resource window

through:

providing contact information for state and federal regulatory agencies,

including names, addresses, and telephone numbers;

offering capsule summaries of applicable state and federal regulations; and

referring the reader to agency home pages and the texts of the regulations

via Web hyperlinks.

Federal Regulatory Requirements

Federal regulations are listed by issuing agency. The relevant federal regulatory

agencies include the U.S. Environmental Protection Agency (EPA), the Department

of the Interior's Bureau of Land Management (BLM), the Bureau of Ocean Energy

Management (BOEM), and the Bureau of Safety and Environmental Enforcement

(BSEE).

EPA regulations

BLM regulations

BOEM and BSEE regulations

State Regulatory Requirements

State regulatory requirements vary widely. Individual state regulations can be

accessed by clicking on a desired state on the U.S. map or by selecting the state

from the pull-down menu.

Alabama Go!

Disclaimer

This regulatory module should not be used as a sole source of information relative

to the regulation of drilling waste management practices. It can only offer a
snapshot in time (as of Winter 2003/04). Agency organization, laws and

regulations, and Web linkages are subject to change; and therefore, the viewer is

encouraged to check with the appropriate regulatory agencies for authorized upto-date information.

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