Environmental Protection for Onshore Oil 

and Gas Production Operations and Leases

API RECOMMENDED PRACTICE 51R

FIRST EDITION, JULY 2009
Environmental Protection for

Onshore Oil and Gas Production Operations and 

Leases

Upstream Segment

API RECOMMENDED PRACTICE 51R

FIRST EDITION, JULY 2009
Environmental Protection for Onshore Oil and

Gas Production Operations and Leases

1 Scope

This standard provides environmentally sound practices for domestic onshore oil and gas production operations. It is 

intended to be applicable to contractors as well as operators. Facilities within the scope of this document include all 

production facilities, including produced water handling facilities. Offshore and arctic areas are beyond the scope of 

this document. Operational coverage begins with the design and construction of access roads and well locations, 

and includes reclamation, abandonment, and restoration operations. Gas compression for transmission purposes or 

production operations, such as gas lift, pressure maintenance, or enhanced oil recovery (EOR) is included; however, 

gas processing for liquids recovery is not addressed. Annex A provides guidance for a company to consider as a 

“good neighbor.” 

2 References

2.1 Normative References

This recommended practice (RP) includes by reference, either in total or in part, the following standards and 

publications. Users should investigate use of the appropriate portion of the most recent editions of the publications 

listed below.

API, API Environmental Guidance Document: Onshore Solid Waste Management in Exploration and Production 

Operations

API, Guidelines for Commercial Exploration and Production Waste Management Facilities 

API Bulletin E2, Bulletin on Management of Naturally Occurring Radioactive Materials (NORM) in Oil and Gas 

Production

API Bulletin E3, Environmental Guidance Document: Well Abandonment and Inactive Well Practices for U.S. 

Exploration and Production Operations 

API Specification 7B-11C, Specification for Internal-Combustion Reciprocating Engines for Oil-Field Service

API Recommended Practice 7C-11F, Recommended Practice for Installation, Maintenance, and Operation of 

Internal-Combustion Engines

API Recommended Practice 11ER, Recommended Practice for Guarding of Pumping Units 

API Bulletin 11K, Data Sheet for the Design of Air Exchange Coolers

API Specification 11N, Specification for Lease Automatic Custody Transfer (LACT) Equipment
4 API RECOMMENDED PRACTICE 51R

API Specification 12B, Specification for Bolted Tanks for Storage of Production Liquids

API Specification 12D, Specification for Field Welded Tanks for Storage of Production Liquids

API Specification 12F, Specification for Shop Welded Tanks for Storage of Production Liquids

API Specification 12J, Specification for Oil and Gas Separators

API Specification 12K, Specification for Indirect Type Oilfield Heaters

API Specification 12L, Specification for Vertical and Horizontal Emulsion Treaters

API Recommended Practice 12N, Recommended Practice for the Operation, Maintenance and Testing of Firebox 

Flame Arresters

API Specification 12P, Specification for Fiberglass Reinforced Plastic Tanks

API Recommended Practice 12R1, Recommended Practice for Setting, Maintenance, Inspection, Operation, and 

Repair of Tanks in Production Service 

API Recommended Practice 49, Recommended Practice for Drilling and Well Servicing Operations Involving 

Hydrogen Sulfide

API Recommended Practice 53, Recommended Practices for Blowout Prevention Equipment Systems for Drilling 

Wells

API Recommended Practice 55, Recommended Practices for Oil and Gas Producing and Gas Processing Plant 

Operations Involving Hydrogen Sulfide

API Bulletin 75L, Guidance Document for the Development of a Safety and Environmental Management System for 

Onshore Oil and Natural Gas Production Operations and Associated Activities

API Recommended Practice 2350, Overfill Protection for Storage Tanks in Petroleum Facilities 

API Publication 4663, Remediation of Salt-Affected Soils at Oil and Gas Production Facilities

NACE RP 0475 1, Selection of Metallic Materials to be used in All Phases of Water Handling for Injection into OilBearing Formations

NACE Standard MR 0175, Petroleum and Natural Gas Industries—Materials for Use in H2S-containing 

Environments in Oil and Gas Production—Parts 1, 2 and 3

 

1 NACE International (formerly the National Association of Corrosion Engineers), 1440 South Creek Drive, Houston, Texas 

77218-8340, www.nace.org.
ENVIRONMENTAL PROTECTION FOR ONSHORE OIL AND GAS PRODUCTION OPERATIONS AND LEASES 5

2.2 References for Operations on Federal Lands

BLM 2, Surface Operating Standards and Guidelines for Oil and Gas Exploration and Development, (The Gold 

Book), 2007 

2.3 References for All Onshore Operations

IOGCC 3, Adverse Impact Reduction Handbook, 2007

3 Acronyms and Abbreviations

BOPE blowout prevention equipment

E&P exploration and production

EOR enhanced oil recovery

ESD emergency shutdown

IC internal combustion

MSDS material safety datasheet

NORM naturally occurring radioactive materials

SOP standard operating procedure

USDW underground sources of drinking water

4 Government Agencies

4.1 General

Before drilling or construction, and, in some instances, before modification of onshore oil and gas production 

facilities, it may be necessary to obtain approvals from one or more government agencies. In addition to drilling and 

building permits, permits may be required because of air emissions, discharges to surface waters or sewer systems, 

injection activities, stormwater discharges (including during construction activities), impacts to threatened or 

endangered species or their critical habitat, impacts to wetlands and other environmental impacts, or impacts to 

other cultural resources. Operators should ensure that all necessary permits have been obtained before 

commencing operations. Operators should ensure that operations are conducted in accordance with local, state or 

federal regulatory requirements.

4.2 Surface Owners and Users

The footprint of drilling and production operations for oil and gas projects is variable and dependent upon the 

operator’s equipment and operational needs, and the mutual objectives established by the operator, appropriate 

regulatory agencies, and the owner of the surface rights. Operators will need to be familiar with land use plans, 

regulations and ordinances that have been adopted by federal, state, and (in certain cases) local governments. 

Different land uses may require operators to adjust their approaches during site preparation, construction, 

development or production to avoid or minimize impacts to existing land uses. The development of surface use 

plans will allow for more efficient use of the land while balancing protection of important local resources, by 

minimizing surface disturbance and mitigating those impacts that are unavoidable.

 

2 U.S. Department of the Interior, Bureau of Land Management, 1849 C Street, NW, Room 5665, Washington, DC 20240, 

www.blm.gov.

3

Interstate Oil and Gas Compact Commission, 900 NE 23rd Street, Oklahoma City, Oklahoma 73105, www.iogcc.state.ok.us/.
6 API RECOMMENDED PRACTICE 51R

Before drilling or construction on lands on which the surface estate is privately held, it is recommended that the 

operator communicate with land owners or surface users concerning activities planned for the site and measures to 

be taken for safety, protection of the environment, and for minimization of impacts to surface uses. Additional 

recommendations may be found in API 75L, Annex B—“Good Neighbor Guidelines.” Operators of federal oil and 

gas leases under private surface ownership are encouraged to consult the BLM publication, Surface Operating 

Standards and Guidelines for Oil and Gas Exploration and Development (The Gold Book) for BLM guidance with 

respect to communication and recommended practices to address concerns of surface owners.

5 Lease Roads

5.1 Introduction

Lease roads are constructed and used to support various exploration and production (E&P) operations. The 

environmental impact of the construction of a roadway can have long lasting effects well beyond the limits of the 

right-of-way. Existing roads should be utilized, where feasible, to limit the extent of new road construction, when they 

meet regulatory standards, transportation and development needs, and safety and environmental objectives. When 

it is necessary to build new roadways, they should be developed in an environmentally acceptable manner 

consistent with landowner recommendations.

5.2 Planning

5.2.1 Road alignment and right-of-way selection is a multidisciplinary process. Goals of the planning effort should 

include affected resource values and safety, and avoidance of haphazard or unnecessary development of roads and 

associated utility corridors. The total infrastructure that may later be developed should be considered during the 

selection process. Government agencies, landowners, tenants, and other users may need to be consulted during 

the planning process.

5.2.2 Standards should be established for the road based on its short-term and long-term function considering 

geography, traffic density, and load expectations.

5.2.3 Alternative alignments should be developed considering the following parameters as appropriate:

a) topography;

b) hydrology, drainage, and watercourses, whether intermittent or permanent;

c) engineering properties of soils, erodible soils;

d) location and amounts of excavation and fill materials;

e) type and location of materials for road construction;

f) air, water, and noise pollution;

g) wetlands and wetland drainage;
ENVIRONMENTAL PROTECTION FOR ONSHORE OIL AND GAS PRODUCTION OPERATIONS AND LEASES 7

h) consistency with community character and local government needs and plans;

i) proximity to dwellings or other permanent structures occupied or used by the public;

j) visual sensitivity;

k) power lines and pipelines;

l) other geotechnical factors, particularly in areas of complex terrain, such as landslide areas, subgrade conditions 

indicating a need for surfacing, potential cut slope problems, and subsurface or surface water problem areas.

5.2.4 Road alignments and potential environmental impacts should be reviewed. Routes and alignment should be 

selected to minimize erosion. Environmentally significant areas should be identified and avoided to the maximum 

extent practical, including:

a) sensitive wildlife and critical habitats;

b) areas with endangered and threatened animals and plants;

c) cultural and historical sites;

d) federal, state, or local areas of concern;

e) areas with the potential for flooding or snow drifting;

f) wetlands.

5.2.5 When required, mitigation strategies should be developed in the planning process, including:

a) road operation schedules and/or use of special designs to minimize any adverse impacts in areas with sensitive 

wildlife and fish habitats, wetlands, existing facilities, crops;

b) plans to take appropriate action on cultural and historic resources before changes are made;

c) maintenance of existing traffic patterns on highways and local access roads.

5.2.6 Interim reclamation plans and final restoration plans should be developed and incorporated into the planning 

process.

5.2.7 Stormwater and air (dust) permit requirements should be considered during the planning phase of the 

roadway.
8 API RECOMMENDED PRACTICE 51R

5.3 Design and Construction

5.3.1 The design and construction of a road should be site-specific. Each road will have its own unique terrain, 

safety, operation, and maintenance requirements. Each area within a route will support a distinct ecology. When site 

conditions are appropriate, where suitable for the types of drilling or production operations anticipated, and where 

compatible with safety and operational concerns, primitive roads may be considered for use as a means to reduce 

resource impacts.

5.3.2 Design and construction documents, including plans and drawings, should be prepared during the planning 

and design phases before the construction of the project. Plans will enable proper and timely review of items of 

environmental concern. They will also be beneficial for later restoration work.

5.3.3 Construction work should be scheduled and the use of special designs and local construction practices 

should be considered to minimize or avoid undesirable effects on sensitive wildlife and fish habitats, wetlands, and 

designated federal, state, or local recreational areas. Seasonal restrictions such as freeze-thaw cycles, potential 

flooding, and wildlife migration should be considered.

5.3.4 The operator should confirm that the construction contractor has implemented an environmental and safety 

program, including the training of construction personnel. This program should include, where applicable, written 

procedures for a hazard communication program, hazardous material handling, spill reporting, emergency response, 

stormwater management, special environmental requirements within the project area, and blasting. The contractor 

should supply material safety datasheets (MSDSs) for all hazardous materials brought on site. Regulatory agencies 

often require performance bonds when roads are to be constructed in environmentally sensitive areas.

5.3.5 The operator should hold a preconstruction meeting with the contractor(s) to establish environmental and 

safety responsibilities along with desired objectives of the project.

5.3.6 Field inspections and lab analysis of soil samples may be used to assess soil erosion hazards and slope 

stability. Properties of soils, length and gradient of slopes, and vegetative cover contribute to soil stability. Fitting the 

profile to topography, locating roads on moderate slopes, providing adequate drainage, and stabilizing slopes 

decreases surface disturbance and reduces erosion and sedimentation.

5.3.7 Means and methods for erosion control are numerous and often site-specific. Revegetation with local 

species, rip-rap, gabions, woven jute, and energy dissipators are effective measures that may be used to reduce 

erosion.

5.3.8 The use of geotextiles and geosynthetics should be considered in road planning and construction. These 

materials offer a variety of applications, aid in stabilizing the road, and minimize the utilization of road bed and 

surface materials.

5.3.9 An adequate drainage system should be incorporated into the design and construction of the road. This

system should efficiently intercept, collect, remove, and discharge water from roads. A drainage system that is 

inadequate or blocked will result in excessive erosion, failures, and higher maintenance costs.

5.3.10 The number of river, stream (including ephemeral streams), lake, and wetland crossings should be 

minimized, where possible. Bridges, culverts, and other drainage structures should be incorporated to ensure the 

free flow of water when drainage ways are intersected. Different flood stages should be considered for the design 

and construction of the crossings.
ENVIRONMENTAL PROTECTION FOR ONSHORE OIL AND GAS PRODUCTION OPERATIONS AND LEASES 9

5.3.11 The use of snow fences should be considered in areas with snow drifting characteristics. Minimization of 

snow buildup will reduce the use of deicers on the roadway and will also reduce the problems associated with the 

disposal of the bladed snow/salt mix during maintenance operations.

5.3.12 Clearing widths should be kept to a minimum. These limits should be delineated and marked in the field. 

Sensitive areas or features should be marked or fenced as required.

5.3.13 Where practical, topsoil should be salvaged and stockpiled in a safe and accessible location and be 

protected from erosion. The stockpiled material should be utilized for revegetation and reclamation purposes.

5.3.14 Revegetation should be done with local plants, seeds, and grasses species. Means and methods will be 

dependent upon seasonal considerations, the specific project area, and government agency requirements.

5.3.15 Areas of excavation should be approved before the start of construction. Permits are required for opening 

pits on federal land and may be required on other public lands. Pit layout and restoration should be planned before 

opening of the pit.

5.3.16 Environmental impacts during coarse/fine borrow material extraction should be minimized. The following 

should be considered:

a) use of recycled road surface material from abandoned roads and locations,

b) use of existing mineral material sites,

c) selecting new sites that minimize environmental impacts,

d) developing upland sites to maximize potential for revegetation and minimize adverse visual impact and possible 

erosion,

e) maintaining a buffer of undisturbed vegetation between borrow pits and highways or other sites.

5.3.17 Warning signs should be provided to comply with local requirements. The signs may include road crossings, 

animal crossings, speed limit, road hazards, pipelines, etc.

5.3.18 Existing pipelines and other subsurface facilities should be identified before construction. These facilities 

should be protected to prevent accidental damage during the construction and operation of the road. 

5.3.19 Measures should be taken to ensure proper and adequate procedures for waste disposal, general 

housekeeping. An effective emergency response plan should be in place before initiating construction. The plan may 

simply be a listing of telephone numbers to call should a utility or product line be damaged. Many times, the existing 

emergency response plan for the field area may be adequate. Construction personnel should be familiar with these 

plans.

5.3.20 Construction activities should be carried out as described in the construction documents, including plans 

and specifications.
10 API RECOMMENDED PRACTICE 51R

5.3.21 Construction supervision should be provided throughout operations. Many potential problems associated 

with incorrect interpretation of construction documents, spills, waste disposal, poaching, and hunting can be avoided 

through proper supervision.

5.4 Primitive or Nonconstructed Roads and Routes

5.4.1 Where site conditions are appropriate, and where approved by a surface owner or surface management 

agency, the establishment and use of “primitive,” two-track roads or overland route corridors may be appropriate for 

an operator’s needs and to facilitate later reclamation of the site. Primitive roads and route corridors may serve as 

appropriate access to exploration drilling locations where it is not certain if the well will be productive, or to producing 

wells where vehicle traffic is infrequent due to the use of off-site production facilities and automated well monitoring. 

Traffic and load expectations for primitive roads should be evaluated. If the expectations are exceeded during the 

project, the road should be evaluated for upgrades.

5.4.2 The appropriateness of primitive roads and routes is both site-specific and use-specific and is typically based 

on many factors, such as anticipated dry or frozen soil conditions, seasonal weather conditions, flat terrain, low 

anticipated traffic, service company’s/driller’s/operator’s access needs. 

5.4.3 Primitive roads or routes necessitate low vehicle speeds and are typically limited to four-wheel drive or highclearance vehicles. They can consist of existing or new roads with minor or moderate grading; two-track roads 

created by the operator’s direct vehicle use with little or no grading; overland routes with a defined travel corridor 

leaving no defined roadway beyond crushed vegetation; or any combination along the route. Operators should not 

flat-blade roads. Drainage must be maintained, where appropriate, to avoid erosion or the creation of a muddy, 

braided course of vehicular travel.

5.4.4 Primitive or two-track roads and routes must be used and established in a safe and environmentally 

responsible manner and are not intended for use as all-weather access roads. Resource damage must be repaired 

as soon as possible and the operator must consult with the surface management agency to determine if all or a 

portion of the road needs to be upgraded to an all-weather access road. When used and maintained appropriately, 

nonconstructed roads and routes have the advantage of reducing construction, maintenance and reclamation costs 

and reducing resource impacts. 

5.4.5 Approval of a surface resource agency is generally required for use of nonconstructed roads on other than 

privately owned lands.

5.5 Maintenance

5.5.1 Proper road maintenance is critical for the performance of the road and to prevent and control erosion and 

sedimentation. Maintenance personnel should be made aware of environmentally difficult and sensitive areas.

5.5.2 Maintenance work should be scheduled and the use of special designs and maintenance programs should 

be considered to minimize undesirable effects on sensitive wildlife and fish habitats, wetlands, and designated 

federal, state, or local recreational areas.

5.5.3 When performing scraping and leveling operations, care should be exercised to avoid disrupting ditches and 

shoulders, and creating undesirable berms with the bladed material.
ENVIRONMENTAL PROTECTION FOR ONSHORE OIL AND GAS PRODUCTION OPERATIONS AND LEASES 11

5.5.4 Ditches, culverts, and drains should be regularly cleaned of debris and sediment to allow the free passage of 

water. Periodic inspections of all culverts should be conducted. Culverts found to be blocked should be cleared.

5.5.5 Borrow and surface materials should be readily accessible to be utilized during maintenance operations. Pits 

opened during construction should be used as a source for maintenance material, where feasible.

5.5.6 The use of dust control materials or measures should be evaluated before their utilization. The materials 

should not be detrimental to health, vegetation, wildlife, or water quality.

5.5.7 Cutting back weed and hedge growth is essential for road safety. This maintenance operation should be done 

with light equipment. Critical review should occur before herbicides or other chemicals used for weed control are 

applied.

5.5.8 There should be continuous monitoring of drainage and erosion control structures. They should be 

maintained and revised, as required, to provide for the intended function.

5.5.9 Erosion should be prevented and controlled. Areas should be revegetated, and slopes and soils should be 

stabilized.

5.5.10 There should be an environmental emergency response plan ready to be placed in action during 

construction and maintenance operations. The plan should include emergency procedures to be followed in the 

event major drainage ways are blocked, fail, or do not perform as required during or immediately after major storm 

events.

5.6 Reclamation and Abandonment

5.6.1 Abandonment procedures should comply with regulatory requirements, contractual obligations, and lessor 

and landowner requirements. Consideration should be given to cost-effective measures that will minimize 

environmental impacts. Interim reclamation should be undertaken for portions of the road or areas disturbed during 

construction of the road that are not required for vehicle travel. In interim or final reclamation, wherever possible, cut 

slopes, fill slopes, and borrow ditches should be recontoured, covered with topsoil and revegetated to restore 

habitat, forage and scenic resources, and to reduce soil erosion.

5.6.2 Abandonment procedures may include the following considerations:

a) restoration;

b) abandonment in place;

c) restoration of original or improved drainage;

d) agreement on maintenance requirements, if any, after discontinued use, to be reached between the operator and 

new user;

e) agency approval requirements.
12 API RECOMMENDED PRACTICE 51R

5.6.3 Restoration plans should be prepared in detail and should consider methods such as:

a) priority of stabilization and revegetation of disturbed areas,

b) use of native plant species,

c) stockpiling soils where reclamation would be enhanced,

d) use of agency approved designs and seed mixes. 

6 Producing, Injection/Disposal Wells

6.1 Completion, Stimulation, and Workover Operations

6.1.1 Planning 

For a new well site, an effective planning process should be carried out and should incorporate the latest guidelines 

for waste management, pit location and construction, handling of water discharges, and waste disposal. The location 

and size of new pits and pads for completion and workover equipment should be selected so as to minimize 

disruption of the surface resources and retain the potential for reclamation of the site. Refer to API Environmental 

Guidance Document: Onshore Solid Waste Management in Exploration and Production Operations for 

environmental aspects of reserve pit construction, operation and closure.

For an existing well site, the planning process is just as important to provide for safe and environmentally acceptable 

completion and workover operations. Existing facilities, such as pits and production equipment, should be reviewed 

and assessed to determine whether the facility is suitable in its present condition for the intended well operations or 

if modifications are required. For both new and existing well sites, a waste management plan for handling and 

storing all waste materials generated during completion and workover activities should be developed. Refer to API 

Environmental Guidance Document: Onshore Solid Waste Management in Exploration and Production Operations, 

for information on how to develop such a plan. The waste management plan should address the specific wastes 

which are expected to be produced by the particular operations being performed, as well as provide guidelines 

concerning the actions to be taken in the event that unexpected waste materials, including hazardous materials, are 

encountered during the operations. In addition to safe handling and storage of waste materials on the well site, 

provisions should also be made for each type of waste to be disposed of. Refer to API 55 and API 49 for planning 

and conducting operations involving hydrogen sulfide. Refer to API E2 for information regarding management of 

naturally occurring radioactive materials (NORM).

Since much of the work on producing and injection wells is performed by contract or service company personnel, the 

operating company should confirm that the contractor’s personnel have appropriate safety training, including hazard 

communication training, and are aware of requirements of the site-specific waste management plan. Consideration 

should also be given to requiring performance bonds, if appropriate. The operator should also confirm that the 

contractor’s personnel are aware of all applicable safety and environmental requirements of the operator.
ENVIRONMENTAL PROTECTION FOR ONSHORE OIL AND GAS PRODUCTION OPERATIONS AND LEASES 13

6.1.2 Equipment Selection

Temporary equipment required to carry out well completion and workover operations should be included in the 

overall operation plan. Equipment should be installed in a manner so as to utilize the smallest practical area for 

prudent operations. Equipment should be maintained to present an acceptable appearance.

6.1.3 Producing Wells 

Producing wells should be completed so production zones and drinking waters zones are isolated and cannot be 

contaminated by other formations. The well must be cased and cemented properly to provide this protection.

6.1.4 Injection/Disposal Wells

Injection/disposal wells should be completed so the injected fluids enter the desired formations and do not enter 

other formations or drinking water zones. Typical injections are completed with three levels of protection for drinking 

water formations:

1) surface casing and cement,

2) long string casing and cement, and

3) tubing and packer.

Also, the area around the injection should be reviewed to see of any wells (active, inactive or abandoned) were 

drilled through the injection/disposal zone. If wells were drilled close to the injection/disposal well that penetrated the 

injection/disposal formation and those wells did not isolate those zones, the injected fluids could flow from the 

injection zone through the improperly plugged or completed well to other oil and gas zones or drinking water zones. 

6.1.5 Remedial Cementing

For both new and existing wells, the known and anticipated needs for remedial cementing to protect underground 

sources of drinking water (USDW) should be considered in the planning stage.

Excess cement, cement returns, and water used to wash cementing equipment should be contained and disposed 

of in an environmentally sound manner. Refer to API Environmental Guidance Document: Onshore Solid Waste 

Management in Exploration and Production Operations for additional information.

6.1.6 Selection, Use, and Storage of Fuels and Completion Fluids

Completion fluid selection should take into account the safety and logistics of transporting, handling, storing, and 

disposing of clean and contaminated fluid. 

For both new and existing well sites, all fuels, treatment chemicals, completion brines, and other similar liquids 

should be properly stored in labeled containers intended for that purpose. Containment should be constructed so 

spilled fuels or chemicals do not reach the ground.
14 API RECOMMENDED PRACTICE 51R

Wherever practical, tanks or existing drilling pits should be used for completion and workover operations. 

Completion brines and other potential pollutants should be kept in lined pits, steel pits, or storage tanks. If a new 

earthen pit is necessary, it should be constructed in a manner that prevents contamination of soils, surface water, 

and groundwater, both during the construction process and during the life of the pit. Consideration should be given 

to the use of tanks or lined pits to protect soil and groundwater, especially for brines and oil-based fluids.

Normal operations should preclude oil in pits. However, in the event that well completion operations dictate use of 

pits containing oil for a brief period of time, they should be fenced, screened, netted and/or flagged, as appropriate, 

to protect livestock, wild game, and fowl. Refer to the Migratory Bird Treaty and Enforcement Improvement Act for 

additional guidance. Oil accumulated in pits should be promptly removed and recovered, recycled, or disposed.

All liquids and other materials placed in pits should be recovered, recycled, or disposed in an environmentally 

acceptable manner (determined by the constituents in the material and the environmental sensitivity of the location).

When operations are completed, pits not required for well operation should be closed in accordance with the 

environmental sensitivity of the location. The surface area should be restored to a condition compatible with the uses 

of the adjacent land area. Any pit retained should be of minimum size commensurate with well operations. Refer to 

API Environmental Guidance Document: Onshore Solid Waste Management in Exploration and Production 

Operations for additional information and permitting requirements.

6.1.7 Stormwater Runoff

Natural drainage patterns of the area should be considered in the location of equipment, pads, and pits so that 

stormwater runoff does not create an environmental hazard by erosion of base material, which could lead to 

equipment instability, or by flooding of pits, which could cause a discharge of oil or other fluids into the local surface 

waters.

Discharges of stormwater from inside E&P facilities such as bermed areas around tank batteries (including oil and 

gas exploration, production, processing, or treatment operations or a transmission facility), which can reach waters 

of the United States, require a stormwater discharge permit and submittal of a stormwater pollution plan to the EPA. 

Contamination includes stormwater that comes into contact with any overburden, raw materials, or waste products 

on the site. 

Construction designs should include installation of erosion and sedimentation control systems. Site construction 

should be inspected routinely and after each significant storm event. Any repairs to the control systems should be 

completed promptly. During the drilling and completion phases, all raw materials should be stored in a manner to 

prevent contaminating the natural runoff of precipitation. Temporary containment and liners should be used to 

minimize the impact of spills and to prevent impacted precipitation from affecting surface or groundwater.

6.1.8 Blowout Prevention Equipment (BOPE)

All BOPE should be selected, installed, and properly maintained in order to prevent uncontrolled releases to the 

environment. Refer to API 53.

All BOPE should have a working pressure rating that exceeds the maximum expected surface pressure.

Training exercises or drills should be held as necessary to ensure crew familiarity and that the BOPE is in good 

working order.
ENVIRONMENTAL PROTECTION FOR ONSHORE OIL AND GAS PRODUCTION OPERATIONS AND LEASES 15

6.1.9 Control of Noise and Other Nuisances

Engines and production equipment should be provided with noise abatement measures, if appropriate, to reduce 

noise levels to the extent practical, considering the local environment. Other nuisances such as odors and dust 

should be controlled as considered appropriate for the location. Consideration should be given to minimizing traffic in 

general, particularly in or near urban areas.

6.1.10 Solids Removal or Capture

All produced fluids, drill cuttings, cement, cement returns, NORM scale, and other solids should be captured and 

classified, then reused, recycled, or disposed. Hazardous waste should be segregated in order to prevent 

contamination of nonhazardous materials.

6.2 Well Operations

6.2.1 Equipment Operation and Maintenance

All well-producing equipment should be kept neat, clean, painted and in good working order. Equipment should be 

painted to blend into the surroundings, if required or appropriate, and kept clean to present an acceptable 

appearance. Selected moving equipment may be painted different colors to enhance visibility.

Safety guards necessary to protect humans, livestock, wildlife, and promote public safety should be maintained 

around equipment. Refer to API 11ER for information on guarding of pumping units. Equipment lockout/tagout 

procedures should also be developed and implemented.

Drip pans should be provided under equipment and storage containers potentially subject to minor leaks. These drip 

pans should be monitored on a routine basis to recover and recycle or dispose of accumulated oil and other liquids.

Bulk storage, recyclable, and reusable containers should be considered in order to reduce the number of containers 

that must be maintained and disposed. All reusable containers should be well marked to denote contents and the 

fact that they are to be reused. 

The installation or use of double stuffing boxes, leak detectors, and shutdown devices should be considered in areas 

of particular environmental sensitivity.

Well cellars should be kept clean, dry, and guarded to prevent accidental falls. Well cellars should be filled if they 

may fill with sour gas and present a safety hazard to people.

6.2.2 Metallurgy and Corrosion

All equipment should be manufactured from materials which are suitable for the environment in which they are to 

operate. NACE MR 0175 and NACE RP 0475 should be consulted for more information.

Equipment operating in known corrosive conditions should be inspected on a routine basis for signs of corrosion, 

with corrective action taken, as needed, to assure the equipment continues to operate in an environmentally 

acceptable manner.
16 API RECOMMENDED PRACTICE 51R

If well production or injection conditions change in terms of hydrogen sulfide or carbon dioxide content, pressure, 

water cut, or any other parameter, the metallurgy of the well equipment should be reassessed to assure its suitability 

for the new conditions.

6.2.3 Leak Detection

All equipment should be inspected on a routine basis for signs of leakage, with corrective action taken, as needed, 

to assure the equipment continues to operate in a safe and environmentally acceptable manner.

All injection and disposal wells equipped with tubing and packed should periodically monitor the tubing casing 

annulus pressure to test the integrity of the tubing and packer. If a well is not completed with a packer, then other 

methods should be used, such as tracer logs or temperature logs to ensure the fluids injected are properly controlled 

and are going into the proper injection/disposal formation. Frequency of testing is dependent on the operating 

conditions. For example, if an area has a high number of corrosion failures, testing for the mechanical integrity of the 

well should be frequent. 

6.2.4 Inspection and Certification

Equipment should be manufactured, refurbished, inspected, and installed according to manufacturer, API or other 

industry standards, and legal requirements.

6.3 Well Testing

6.3.1 Venting and Flaring

Venting and flaring should be restricted to a safe location. Where possible, the flare or vent should be located 

downwind considering the prevailing wind direction at the well location. When possible, all gas resources of value 

should be captured and used. If not possible, then this gas should be flared.

6.3.2 Flare Pits

Flare pits, sometimes called blowdown or emergency pits, should not be used for storage or disposal. The primary 

purpose of a flare pit is to catch any incidental fluid that might be associated with the gas stream that does not burn. 

Fluids in a flare pit should be removed daily, or as quickly as practical.

Siting and construction of flare pits should minimize the risk of surface and groundwater contamination. The size of 

the flare pit should be proportionate to the volume of liquid effluent that might be expelled from the gas flare. Use of 

a knockout vessel should be considered.

6.3.3 Control of Noise and Other Nuisances

Flares may need to be provided with noise abatement measures to maintain noise levels compatible with the local 

environment. The noise intensity, duration, location relative to public areas and natural resources, as well as the 

flare/vent exit design should be considered, where applicable.
ENVIRONMENTAL PROTECTION FOR ONSHORE OIL AND GAS PRODUCTION OPERATIONS AND LEASES 17

Other nuisances, such as light emittance from a lighted flare, odors, and dust, should be controlled as considered 

appropriate for the location.

6.4 Plugging and Abandonment 

6.4.1 General

Permanent abandonment is done when the wellbore has no further utility and is permanently sealed against fluid 

migration. Temporary abandonment operations may be performed when a wellbore has future utility, such as for 

EOR projects, and must be maintained in a condition where routine workover operations can restore a wellbore to 

service. The same environmental concerns exist in both cases. Refer to API E3.

6.4.2 Subsurface

6.4.2.1 General

Several environmental concerns related to well abandonment should be addressed. The primary environmental 

concerns are protection of freshwater aquifers and USDW, as well as isolation of downhole formations containing 

hydrocarbons or used for injection. Additional issues, which should be evaluated, are the protection of surface soils 

and surface waters, future land use, and permanent documentation of abandoned wellbore locations and conditions.

6.4.2.2 Plugging Purpose

The purpose of plugging wells is to prevent interzonal migration of fluids; the contamination of freshwater aquifers, 

surface soils, and surface waters, and to conserve hydrocarbon resources either in the production interval or 

potential production intervals. Generally, contamination by an improperly plugged and abandoned well can occur in 

two ways:

a) the abandoned well can act as a conduit for fluid flow between penetrated strata, into USDW, or to the surface;

b) contaminated water can enter the abandoned wellbore at the surface and migrate into USDW.

Such contamination is prevented when a well is properly plugged. Not only do the plugging operations prevent an 

abandoned well from becoming a conduit for contamination to occur, but well construction and completion methods 

also contribute to the prevention of contamination.

Well plugging operations are focused primarily on protecting USDW, isolating downhole formations productive of 

hydrocarbons or used for injection, and protecting surface soils and surface waters. A surface plug prevents surface 

water runoff from seeping into the wellbore and migrating into USDW cement plugs isolating hydrocarbon and 

injection/disposal intervals and a plug at the base of the lowermost USDW accomplish this primary purpose. Surface 

water entry into an abandoned well is a concern because the water may contain contaminants from agricultural, 

industrial, or municipal activities. API E3 recommends that operators set a cement plug at the base of the lowermost 

freshwater aquifer or USDW during plugging and abandonment operations applicable to the well.

NOTE The cement plugs also work to protect surface soils and water from wellbore fluids by confining those fluids in the well. 
18 API RECOMMENDED PRACTICE 51R

In addition to the cement plugs described herein, many state and federal regulatory agencies require cement plugs 

across the base of the surface casing and in, or between, each producing and potential producing zone.

6.4.2.3 Fluid Confinement

It is essential that all formations bearing usable quality water, oil, gas, or geothermal resources be protected and/or 

isolated. The prevention of gas or fluid migration to other zones or to the surface is of primary importance. Openhole plugs, casing plugs, or cement squeezed through casing perforations will isolate the target formations in most 

cases. However, special procedures, such as perforating casing and circulating cement, may be necessary to isolate 

that potential production or injection formations existing behind uncemented casing. It is important to prevent 

interzonal flow in an abandoned well so that such cross-flow does not interfere in the commercial exploitation of the 

zones through nearby wellbores.

6.4.3 Surface

6.4.3.1 General

The cleanup and remediation of the surface may include cutting off the surface casing below ground level, restoring 

the surface to conditions near those that existed prior to the well being drilled, and marking the surface of the 

wellbore by installing an upright marker. The operator should restore the well site consistent with the criteria 

presented in API Environmental Guidance Document: Onshore Solid Waste Management in Exploration and 

Production Operations. However, the landowner should be consulted before beginning well site remediation. Some 

states require that the landowner be notified that a well is to be plugged. The landowner may have a right to use the 

well for a freshwater source.

6.4.3.2 Cleanup and Remediation

Assuming the landowner elects not to use the well as a freshwater source, the operator should set the required 

surface plugs; remove the wellhead; weld a steel plate on the surface casing stub, if required; fill in the well cellar, rat 

hole and mouse hole; and level the area. Casing strings left in the well should be cut off 3 ft to 6 ft below ground 

level, or deeper if required by the landowner.

Pits should be emptied and reclaimed to a condition similar to the rest of the reclaimed pad area. Pits should be 

allowed to dry or be solidified in situ before filling. The pit area may be mounded to allow for settling. Before 

removing or abandoning pipelines or flowlines, fluid displacement and line purging should be considered and fluid 

reclaimed, recycled, or properly disposed of according to fluid type.

Open burning can be used in some areas to dispose of nonhazardous, hydrocarbon-containing wastes that are 

unsuitable for recycling. Burning should be restricted to materials such as oily sorbents and paraffin and should be 

conducted only with approval of state or local air pollution regulatory agencies. Burning should be conducted during 

daytime hours and with due regard to wind direction and velocity. The results should not cause a nuisance that could 

result in black smoke or particulates.

Off-site commercial facilities should be used for other nonhazardous and hazardous waste disposal. The off-site 

facilities should be permitted and care should be taken with site selection. Refer to API Environmental Guidance 

Document: Onshore Solid Waste Management in Exploration and Production Operations, API 4663 and API’s 

Guidelines for Commercial Exploration and Production Waste Management Facilities. 
ENVIRONMENTAL PROTECTION FOR ONSHORE OIL AND GAS PRODUCTION OPERATIONS AND LEASES 19

6.4.3.3 Soil Erosion

Disturbed areas, such as roads, pits, and well sites, may need to be further remediated depending on lease 

agreements.

6.4.3.4 Inspection

Final abandonment is complete only after all surface equipment is removed, all pits are closed, and the surface is 

restored. A vertical steel monument may be considered that indicates the well location, operator, and well number. 

Thereafter, the abandoned well site can more easily be located and the former operator determined.

7 Lease Gathering and System Lines 

7.1 Introduction

In planning lease gathering and system lines, including electrical distribution systems, it is important to consider the 

impact that construction operations and maintenance activities will have on people, animals, plants, and the land 

itself, both surface and shallow subsurface. The impact on current use, as well as possible future uses, should be 

evaluated along with potential future facilities expansion. Because pipelines can be buried, and the surface 

reclaimed, long-term surface disturbance associated with pipelines can be avoided. The placement of pipelines 

should avoid steep hillsides and watercourses where feasible. Also, where feasible, pipeline routes should take 

advantage of road corridors to minimize surface disturbance. Also, when clearing is necessary, the width disturbed 

should be kept to a minimum and topsoil material should be stockpiled to the side of the routes where cuts and fills 

or other disturbances occur during pipeline construction. Retaining topsoil for replacement during reclamation can 

significantly accelerate successful revegetation.

7.2 Route Selection

7.2.1 The following environmental factors should be considered in planning lease gathering and system lines.

a) Proximity to lakes, streams (including dry washes and ephemeral streams), wetlands, drainage and irrigation 

ditches, canals, flood plains, and shallow water wells. These features should be evaluated in terms of 

disturbances during construction and routine operations, and in the event of accidental releases.

b) Depth to, and quality of, groundwater. The potential impact to groundwater, particularly from any releases from 

buried lines should be considered.

c) Removal of trees, disturbances to dikes, levees, and terraces, and destruction of growing crops. These impacts 

should be evaluated with a focus on construction and routine maintenance activities.

d) Impacts to migratory bird habitat or critical habitat of threatened or endangered plant and animal species, 

including noise and dust.

e) Proximity to buildings or other facilities occupied or used by the public. Particular consideration should be given 

to homes, churches, schools, and hospitals.
20 API RECOMMENDED PRACTICE 51R

f) Impact on cultivated lands.

g) Areas of special historical, archeological, recreational, biological, or scenic significance.

h) Land ownership.

i) Location of recently active shallow faults.

7.2.2 The selection of routing for lease gathering and EOR injection and produced water disposal system lines, 

consistent with production, EOR and disposal requirements and overall economics, should consider the following:

a) foreseeable uses of surfaces areas by either the landowner or tenant;

b) possible exposure to future construction and excavation work;

c) topography, when it is an important factor in:

1) line design,

2) right-of-way maintenance,

3) possible land erosion,

4) emergency response and containment of releases;

d) location of existing rights-of-way;

e) location of existing roads.

7.3 Design

7.3.1 In design of lease gathering and system lines, appropriate industry codes should be followed.

7.3.2 Lease gathering and system line design should consider the following.

a) Estimated life of the line.

b) Line environment (nature of the soil, presence of water-saturated soil, alkaline flats, depth of frost, etc.).

c) Nature and quantity of product throughput, initially and as production matures, including the potential for EOR 

processes.

d) Impacts on existing facilities.

e) Consequences of possible line failure. Release of oil, water, or gas should be qualitatively evaluated. 

Consideration should be given to installing block valves to isolate line segments located in or near 

environmentally sensitive areas (such as wetlands), on either side of stream crossings, and in close proximity to 
ENVIRONMENTAL PROTECTION FOR ONSHORE OIL AND GAS PRODUCTION OPERATIONS AND LEASES 21

areas occupied by the public. Consideration should also be given to sleeving lines or using heavier walled pipe in 

these areas.

The qualitative evaluation should consider the following:

1) public impact,

2) environmental impact (including potential natural resource damage assessment liability),

3) damage to crops and domesticated animals,

4) cleanup costs,

5) political or regulatory impacts.

f) Corrosion inhibition measures (external and internal). All equipment should be manufactured from materials 

which are suitable for their operating environment. NACE MR 0175 should be consulted for further guidance, as 

applicable.

g) Burial to optimum depth to reduce exposure to hazards such as plowing, freezing, and other construction.

h) Provisions for various crossings (roads, streams, and other lines).

i) Optimum location for blowdown tanks, valves, etc.

j) Noise abatement (where appropriate).

k) Miscellaneous variable factors including operating pressures, temperature changes, line expansion, and desired 

safety factors.

l) If electrical distribution lines are to be installed in areas where raptors are likely to use them as perches, 

consideration should be given to installing wooden perch guards or cross members on the poles above the lines 

to prevent the birds from coming in contact with the charged lines.

7.4 Construction and Installation

7.4.1 Lease line routes and applicable rights-of-way should utilize the smallest practical surface area, consistent 

with prudent operations. 

7.4.2 Unnecessary damage to trees and other vegetation adjoining lease line routes should be avoided.

7.4.3 If contractors are used to install lines, the operator should verify that the contractor has implemented a safety 

program that includes a written hazard communication program. The contractor should supply MSDSs for all 

hazardous materials brought on site.

7.4.4 Appropriate inspections should be performed during construction to ensure design specifications are met.
22 API RECOMMENDED PRACTICE 51R

7.4.5 Upon completion, lines should be inspected and pressure tested for possible leaks in accordance with state 

and local codes. Pressure test fluids should be collected and disposed. Refer to the API Environmental Guidance 

Document: Onshore Solid Waste Management in Exploration and Production Operations for recommendations for 

disposal of these test fluids.

7.4.6 After installation of a new line, all lease line routes and rights-of-way should be cleaned up and restored to 

conditions compatible with existing land use, unless other arrangements have been made with the landowner. 

Disposal of all waste should be in accordance with the API Environmental Guidance Document: Onshore Solid 

Waste Management in Exploration and Production Operations.

7.4.7 Line routes and burial depth should be adequately documented to aid in preventing ruptures and/or 

accidental leaks during future excavation activities. Crossings should be marked.

7.5 Operation and Maintenance

7.5.1 All applicable personnel (both company and contractor) should receive training to provide for proper 

operation and maintenance of the lines. This training should include start-up and shutdown procedures, normal 

operating procedures, and emergency response procedures, in the event of a leak or spill of a hazardous substance. 

7.5.2 Line routes and facilities should be inspected at intervals dictated by evaluation of exposures and/or failures.

7.5.3 Appropriate steps should be taken to prevent surface and environmental damage from the use of hot oil, 

chemicals, and other treatments that are used to maintain lease gathering and system lines.

7.5.4 Proper maintenance practices should be exercised with respect to crossing markers, blowdown tanks, 

venting equipment, and corrosion protection equipment. Blowdown fluids should be collected and placed in the 

production system to recover hydrocarbons. Waste materials should be recycled, reclaimed, or disposed. Refer to 

API Environmental Guidance Document: Onshore Solid Waste Management in Exploration and Production 

Operations.

7.5.5 Pressure tests, profile surveys, and other means should be considered to meet operating safety 

requirements.

7.5.6 Operating procedures should provide for early identification of developing corrosion problems, failure-prone 

equipment, and malfunctions so that corrective action can be taken before environmental or safety consequences 

occur. Frequency of failure analysis should be considered to aid in scheduling line replacements.

7.5.7 Appropriate industry codes should be followed with respect to maintenance of records, repairs, reporting of 

leaks, etc.

7.5.8 Whenever modifications are made to existing lines or there are significant changes in physical parameters 

(temperature, pressure, composition, etc.), the changes should be considered for evaluation pursuant to 

management of change principles. Where appropriate, facility drawings should be updated to show modifications 

and the superseded drawings should be destroyed.
ENVIRONMENTAL PROTECTION FOR ONSHORE OIL AND GAS PRODUCTION OPERATIONS AND LEASES 23

7.6 Abandonment of Gathering and System Lines 

7.6.1 All surface lines should be removed. Lines should be purged before removal.

7.6.2 Surface and subsurface equipment connected to buried lines should be removed to a depth consistent with 

subsequent land use or, preferably, to the depth of the buried lines.

7.6.3 Harmful or hazardous materials should be displaced from any lines abandoned in place.

7.6.4 Where appropriate, each outlet of abandoned lines should be permanently sealed.

7.6.5 All crossing markers and other line markers should be removed.

7.6.6 The location of abandoned lines should be identified on facility maps.

7.6.7 Upon completion of abandonment activities, all disturbed surface areas should be cleaned up and restored to 

conditions similar to the adjacent lands.

7.6.8 Dispose of all waste per API Environmental Guidance Document: Onshore Solid Waste Management in 

Exploration and Production Operations.

8 Production and Water Handling Facilities 

8.1 Requirement Determination (Preplanning Considerations)

The overall basis for siting, designing, constructing, and operating oil, gas, and water production, handling, and 

disposal/injection facilities should be to minimize adverse effects on the environment, consistent with providing an 

economical means of accumulating well, lease, or unit production from primary, secondary, or tertiary recovery 

methods and producing the ultimate recoverable reserves. Impacts on local population, land, surface and 

subsurface waters, air quality, and animal and plant species, including habitat, should be considered.

Water handling facilities are typically located adjacent to, or within, production facilities. Initial planning for these 

facilities within a field should consider future development potential in order to minimize surface disturbance. When 

practical and economic, central field locations should be considered to avoid the use of multiple facilities. Facility 

sizing should consider future throughput increases to minimize the need for additional tankage and treating vessels.

Production and water handling facilities should be planned to utilize the smallest practical surface area consistent 

with safe, prudent, and economic operations. In addition, produced water may be saline and corrosive. Therefore, 

special care should be taken to minimize the possibility of environmental damage due to equipment upsets, spills, 

and leaks.

Baseline conditions and past land-use in the area should be documented. At a minimum, drinking water supplies 

should be identified and sampled before any development. Water usage should be determined during the planning 

phase so that water rights can be secured and disposal options evaluated and selected.
24 API RECOMMENDED PRACTICE 51R

8.2 Site Selection Considerations

8.2.1 Land Use

Topographic, population, environmental hazard, zoning, and other maps should be consulted, where applicable, to 

locate sensitive or high exposure areas [such as churches, schools, hospitals, residential areas, surface waters, 

freshwater wells, flood zones, active fault areas, threatened and endangered plants and animals (including habitat), 

migratory bird habitat, wetlands, archeological, recreational, biological, or scenic areas]. Where feasible, the site 

should be located away from these sensitive areas. The potential impact from upset conditions, such as oil or 

produced water spills and leaks, should be considered.

Final well patterns should be considered, if possible, to minimize right-of-way requirements for roads and lease lines. 

Existing roads and rights-of-way should be utilized to the maximum extent possible.

The land owner and/or surface tenant should be consulted to consider present and future uses of affected and 

adjacent land.

Production and water handling facilities should be planned to utilize the smallest practical surface area consistent 

with safe and prudent operations. Future expansion possibilities should be considered.

On federal or state administered lands, appropriate agencies should be consulted in advance with respect to land 

use and environmental issues.

8.2.2 Erosion and Drainage

A site should be selected that minimizes the amount of surface terrain alteration to reduce environmental and 

aesthetic damages. Cuts and fills which pose possible landslide or slump problems should be avoided. 

Consideration should be given to stock piling topsoil, if feasible.

The natural drainage patterns of the land should be considered in selecting the site. Adequate culverts and drainage 

ditches should be provided, as required by the terrain. Soil stabilization, such as sod or grass seeding, should be 

provided to prevent erosion. Unnecessary removal of trees or alteration of other natural features should be avoided.

8.2.3 Water Resources

The proper management of water resources during the development and operations phases of oil and gas 

production is directly related to minimizing surface disturbances. Water can be used to create optimal soil moisture 

conditions to allow for proper compaction of soils, thereby, minimizing surface degradation caused by vehicular 

traffic and the occurrence of erosion events. Water is also important to help suppress dust and is necessary for 

drilling, completion and hydraulic fracturing activities. Since a large volume of water is often generated during the oil 

and gas production process, especially for coalbed natural gas production, additional surface disturbances may 

result without proper produced water management plans. For example, additional surface water can affect water 

quality, cause changes to channel morphology in nearby streams, or cause damage to access roads. The release of 

produced water typically can be controlled to prevent surface disturbances by utilizing management practices 

appropriate to the location or circumstances. Depending on the region, local geology and water quality, produced 

water may be used to support livestock/wildlife watering or for use in irrigation systems. Where it is allowed by 

regulatory authorities, the water can also be discharged into appropriate water systems or reinjected into suitable 

reservoirs. 
ENVIRONMENTAL PROTECTION FOR ONSHORE OIL AND GAS PRODUCTION OPERATIONS AND LEASES 25

8.2.4 Subsurface Soil Conditions

Subsurface soil conditions should be considered for adequate foundation support of buildings, pumps, engines, 

tankage, and equipment used in the construction process.

Soil characteristics should be evaluated for construction of dikes, firewalls, and emergency containment areas. 

Lining of containment areas with compacted clay or synthetic liners should be considered where porous soil 

conditions exist or groundwater could be impacted.

Soil corrosiveness or resistivity should be evaluated to determine whether coating or wrapping of lease lines will be 

necessary to prevent or control corrosion. Cathodic protection should be considered for highly corrosive conditions 

or sensitive areas.

8.2.5 Fire Protection

Production and water handling facilities should not be located where the equipment will create a potential fire 

hazard. As applicable, proper fire safety equipment should be stored nearby.

8.2.6 Public Exposure

In noise control planning, production and water handling facilities should be located as far as practical from buildings 

or facilities occupied or used by the public. 

Facilities should be located to minimize risk of public exposure from potential hazardous material releases, 

considering prevailing winds and topographic elevations to the maximum extent practicable. 

8.3 Facility Design

8.3.1 Equipment Sizing, Specifications, and Design

Consideration should be given to the following items in designing and constructing production facilities.

a) Production-related equipment should be sized and designed to provide appropriate safety and utility. Future 

development and exploration plans should be considered when sizing equipment. Where appropriate, the 

facilities should be sized to handle current and future production to minimize retrofitting and improper use of 

equipment. Equipment should be designed with appropriate spill control devices, such as high-/low-level 

indicators or high-/low-pressure indicators, to improve safety and protection of the environment.

b) The anticipated time the equipment is expected to remain active should be considered. Proper design and 

installation can minimize future equipment failures and downtime.

c) Equipment and foundations should be designed and installed giving consideration to adverse natural conditions 

common to the area, such as floods, excessive snow and rain, earthquakes, tornadoes, hurricanes, and dust 

storms.
26 API RECOMMENDED PRACTICE 51R

d) Equipment installations should comply with industry standards. Air pollution control facilities should be installed 

whenever practical, economical, and technically feasible. Flaring vs venting should be evaluated based on gas 

volume and composition, safety, economics, and local environmental impact.

e) Pressure requirements for vessels, lines, and other equipment should be considered. Any variance from the 

manufacturer’s recommended rates or pressures should be evaluated thoroughly. Refer to API 12J for 

information on sizing and designing lease pressure vessels.

f) The following items should be considered in installing fired lease vessels.

1) Consideration should be given to surrounding facilities when selecting the placement of fired lease vessels.

2) Manufacturer’s recommendations should be followed. Any variances from these recommendations should be 

evaluated thoroughly.

3) Fired lease vessels should not be located immediately adjacent to oil, gas, or any other flammable or 

explosive storage facilities. Facilities should have a grade established so that releases of flammable fluid drain 

away from fired equipment.

NOTE Some states have minimum distance requirements between fired vessels and storage facilities. 

4) Vessels should be well maintained and free of unnecessary debris or flammable products.

5) Fencing or some form of guarding should be considered to protect the public, livestock, and wildlife.

6) Refer to API 12K and API 12L for some information on selecting and designing fired lease vessels.

7) Consideration should be given to air permitting requirements for fired lease vessels.

g) The following items should be considered in installing bulk storage and loading facilities.

1) Adequate fire/retaining walls or other containment measures should be provided around tanks, where 

necessary to comply with regulatory requirements, in order to contain accidental discharges and prevent 

environmental damage. No open pipes should extend from within the firewalls which might allow contaminated 

fluids to be drained or siphoned from inside the containment area. 

2) Installation of impervious foundations or liners under storage tanks should be considered to allow detection 

and containment of fluid releases.

3) Installation of high-level alarms and/or monitors should be considered on tankage.

4) Installation of drip pans or other containment should be considered at truck or barge loading/unloading hose 

connections to contain any spillage.

5) Emission permits should be obtained based on the highest anticipated production rates and equipment 

specifications before installation of the facilities or commingling well production to central facilities.

6) The following API recommended practices and specifications should be considered in designing storage and 

loading facilities:

i) API 11N, 

ii) API 12B, 
ENVIRONMENTAL PROTECTION FOR ONSHORE OIL AND GAS PRODUCTION OPERATIONS AND LEASES 27

iii) API 12D, 

iv) API 12F, 

v) API 12N, 

vi) API 12P.

h) The following items should be considered in installing internal combustion (IC) engines and compressor facilities.

1) Consideration should be given to minimizing noise disturbance. IC engines and compressor facilities should 

be located as far as practical from areas accessible to the general population. If feasible, alternate types of 

prime movers, such as electric motors, should be considered.

2) The emissions generated by the engine(s) exhaust should be of concern. Appropriate lead-time for permitting 

should be allowed, as it may require from six (6) months to one (1) year to permit compressor facilities. All 

required construction and emissions permits must be obtained before construction, modification, or relocation 

of an engine is initiated. The type of fuel should be selected to minimize pollutants. Electric power should be 

considered, where feasible.

3) Consideration should be given to installing drip pans or placing engines and compressors on impervious pads 

to minimize the impact of potential oil and chemical drips and spills. If drip pans or impervious pads are used, 

special attention should be given to ensuring that they are kept clean and that any oil or chemical collected is 

removed, recovered, and recycled or disposed in a timely and proper manner.

4) Piping for the relief valves of compressors should be of adequate size and piped to an appropriate vent or 

flare.

5) Placing fences, guard walls, or buildings around all engines and compressors should be considered for the 

protection of the public and any livestock or wildlife.

6) The following API standards and publications should be considered when installing and maintaining IC 

engines and compressor facilities:

i) API 7B-11C,

ii) API 7C-11F, 

iii) API 11K.

i) The following items should be considered in planning, installing, and using pits, firewalls, and dikes.

1) Whenever practical, tanks should be used instead of pits.

2) Existing pits should be minimized and alternate means considered, where feasible. Pits should only be used 

for the purpose they were intended. Personnel should be advised on the specific use of the pit and what 

substances are allowed in the pit.

3) During the design and construction of pits and firewalls, necessary precautions should be taken to protect 

ground and surface water, crops, trees, livestock, and wildlife.

4) Pits should be designed and constructed to have sufficient freeboard, or provide adequate reserve capacity, to 

prevent overflow under maximum anticipated operating requirements and precipitation.
28 API RECOMMENDED PRACTICE 51R

5) Pits should be fenced or otherwise equipped, as necessary, for public safety and to protect livestock and 

wildlife.

6) Netting of pits should be considered to protect migratory birds from exposure to the pit contents if there is a 

potential for the pit to have an oily surface or to contain potentially harmful substances. 

7) Burn pits should be located where prevailing winds will reduce fire hazards and smoke nuisance.

8) Storage vessels for liquid hydrocarbons, saltwater, chemicals, or other fluids that are not acceptable to be 

discharged into the local environment should have dikes constructed around their perimeters.

9) Dikes and firewalls should be constructed of material to prevent the release of fluids to the local environment 

during an accidental or emergency discharge from their original containment.

10) Consideration should be given to designing dikes and firewalls with a sufficient perimeter and wall height to 

contain the maximum volume of the largest vessel or tank contained within, and with sufficient freeboard for 

maximum rainfall and snow melt. Any drain lines through dikes should be equipped with valves/blinds that are 

normally closed and locked.

j) The following items should be considered in using utilities at production sites:

1) existing utilities should be considered in the design of production and water handling facilities;

2) if electricity is available, the use of electric motors/prime movers should be considered to minimize air 

emissions and noise;

3) storage facilities should not be located under or near major electrical transmission lines;

4) all electricity, potable water, sewage, and municipal gas lines should installed in accordance with any 

applicable codes or regulations. 

k) The following items should be considered in designing and installing flares/vents at production sites.

1) Flares/vents utilized in production facilities should be located downwind (with respect to prevailing wind 

direction) from the installation and at a proper safe distance from the related equipment.

2) The surrounding environment should be considered when designing flares. The flare should be located far 

enough from trees and other vegetation to ensure they will not be ignited during times of maximum flare and 

strong winds. Installation of liquid scrubbers should be considered.

3) Flares and vents, assuming vent ignition, should be of sufficient height to protect workers and the public during 

maximum flaring/venting and strong winds.

4) Fencing around flares should be considered to protect the public, livestock, and wildlife.

5) Installation of automatic igniters, rather than standing pilots, should be considered, where feasible, to conserve 

natural gas and reduce emissions. 

6) Flares should be of a smokeless design, if possible.

7) Consideration should be given to design features which will prevent raptors or other birds from perching on 

flares.
ENVIRONMENTAL PROTECTION FOR ONSHORE OIL AND GAS PRODUCTION OPERATIONS AND LEASES 29

l) Safety systems for protecting the environment should be considered as follows.

1) Installation of safety equipment and systems should be considered, i.e. emergency shutdown (ESD) systems 

which have the ability to shut wells in, shut down compressors or other engines, or divert production during 

malfunctions or accidental releases. Where appropriate, alarm systems should be installed to notify the public 

or company officials of equipment failure or accidental releases. Equipment for fire protection should be 

installed and maintained, such as, fire extinguishers, spray nozzles, fire pumps, water storage, and automatic 

extinguishers.

2) API 2350 should be considered in the design of safety systems.

m) Corrosion abatement procedures should be considered as follows.

1) The corrosiveness of the anticipated gas or fluid should be considered during the design and selection of the 

equipment.

2) Where corrosion problems are anticipated, a corrosion abatement program should be established to minimize 

the potential for leaks.

3) Soil corrosiveness or resistivity should be evaluated for necessity of coating or wrapping of lines to be buried. 

In some cases, cathodic protection may be necessary.
30 API RECOMMENDED PRACTICE 51R

n) Special consideration should be given to reducing air emissions associated with production and water handling 

facilities. The following items should be considered during design and construction of these facilities:

1) vapor recovery units and flares;

2) catalytic converters on fired equipment exhaust;

3) minimization of benzene, hydrogen sulfide, and other hazardous emissions from tanks, glycol reboilers, and 

other equipment;

4) minimization of operational gas vents, leaks, and discharges from pneumatic controls and other equipment; 

5) electric powered prime movers;

6) valves installed on dead end piping should be capped, plugged, or sealed by a blind flange.

8.3.2 Equipment Location

a) Production and water handling facilities should be located where they do not present a fire hazard to nearby 

facilities. Fired vessels, IC engines, flares, or other equipment that produce sparks or flames should be 

appropriately separated from oil and gas storage facilities. Topographic and other maps should be consulted to 

determine if operational problems would affect the local environment. This could include, but is not limited to, the 

possibilities of oil or water discharges draining into surface waters. Minimization of damage to vegetation crops, 

forests, animal habitation, etc. should also be considered. Unnecessary removal of trees, excessive grading, or 

alteration of other natural features should be avoided.

b) In populated areas, the location of equipment should take advantage of prevailing winds in order to ensure public 

safety in the event of equipment malfunction, release, or fire. In all cases, production and water handling facilities 

should be located as far as practical from buildings occupied or used by the public.

c) Noise levels of production and water handling facilities should be considered when operating near populated 

areas. 

d) Equipment should be located with consideration given to subsurface soil conditions such that there is an 

adequate foundation to support the facilities to be constructed and the equipment to be used in the construction 

processes.

e) The location of all wells should be considered to minimize rights-of-way requirements for lease roads and 

gathering lines.

8.3.3 Waste Management

a) Equipment and facilities should be located and designed to minimize the wastes generated by operations and 

maintenance activities.

b) Recyclable products should be used, where possible. Bulk storage, recyclable, and reusable containers should 

be considered to minimize waste.
ENVIRONMENTAL PROTECTION FOR ONSHORE OIL AND GAS PRODUCTION OPERATIONS AND LEASES 31

c) Appropriate methods of collecting and recycling or disposing of waste generated during construction, operation, 

and maintenance of the facility should be considered.

d) Operators should develop waste management plans. Refer to API Environmental Guidance Document: Onshore 

Solid Waste Management in Exploration and Production Operations for additional information.

8.4 Construction Considerations

8.4.1 Site Preparation

The following site preparation steps must be taken before initiating construction:

a) soil characteristics should be checked to determine the appropriate foundation design for the site;

b) the size and type of equipment to be used during construction should be considered to allow sufficient room to 

work in a safe manner;

c) adequate culverts and drainage ditches should be provided as required by the local environment;

d) the open end of lines under construction should be temporarily capped at the end of each workday if a line could 

be accessible to wildlife.

8.4.2 Inspection and Testing

The following inspection and testing steps must be taken before initiating construction.

a) During construction, qualified personnel to ensure that design specifications are met should perform appropriate 

inspections to ensure that design specifications are met.

b) Upon completion, equipment and facilities should be inspected for possible leaks. If necessary, equipment 

should be pressure tested in accordance with applicable codes. If fluids are used to pressure test, collect and 

dispose of the fluids, refer to API Environmental Guidance Document: Onshore Solid Waste Management in 

Exploration and Production Operations for applicable information.

c) X-raying of welds should be considered in critical areas where extreme pressure or corrosiveness is anticipated 

or where potential risk to the local environment is of great concern.

8.4.3 Qualification of Personnel

The qualifications of personnel working on the construction site should be evaluated to aid in ensuring the work will 

be properly performed.

8.4.4 Selection of Contractors

Consideration should be given to requiring contractors to have performance bonds should be considered when 

facilities are to be constructed in environmentally sensitive areas.
32 API RECOMMENDED PRACTICE 51R

8.4.5 Equipment Installation

All equipment should be installed in accordance with the original design of the equipment. Any variations from the 

original specifications should be evaluated thoroughly to ensure safety of the operations. Refer to API 12R1 and API 

7C-11F for information regarding equipment installation.

8.4.6 As-built Drawings

Upon completion of facilities, the original drawings or schematics should be updated, as required. Changes or 

modifications from the original design or drawings should be noted for future reference.

8.4.7 Site Cleanup

Unused and excess construction materials should be properly stored or removed from the site upon completion. 

During construction, the site should be kept as clean and free of debris as possible. Where feasible, unused material 

should be removed from the construction site as it is determined to be surplus. Where applicable, construction waste 

should be recycled. Refer to API Environmental Guidance Document: Onshore Solid Waste Management in 

Exploration and Production Operations for additional information regarding management of waste.

8.4.8 Interim Reclamation

Interim reclamation consists of minimizing the footprint of disturbance by reclaiming to the extent possible all 

portions of the site not required for production operations. The portions of the cleared site not needed for operational 

and safety purposes are recontoured to a final or intermediate contour that blends with the surrounding topography 

as much as possible. Sufficient level area remains for the set-up of workover or production stimulation and to park 

necessary equipment. Where practical, the operator should spread topsoil over the entire location and revegetate as 

closely as possible to the production facilities, unless an all-weather, surfaced access route or turnaround is needed 

to inspect or operate the well or to complete workover or stimulation operations. It may be necessary to drive, park 

and operate on restored, interim vegetation within the previously disturbed area. This is acceptable provided 

damage is repaired and reclaimed following use. To reduce final reclamation costs and effort, to maintain healthy, 

biologically active topsoil, and to minimize habitat, visual resource, and forage loss during the life of a well, salvaged 

topsoil should be spread over the areas of interim reclamation rather than stockpiled.

Where the topography is flat and it is, therefore, unnecessary to recontour the well location at the time of final 

reclamation, the operator should set aside sufficient topsoil for reclamation of the small unreclaimed area around the 

wellhead. Any topsoil pile set aside should be revegetated to prevent it from eroding and to help maintain its 

biological viability. On sloped ground, during final reclamation the topsoil and interim vegetation must be restriped 

from portions of the site that are not at the original contour, the well pad recontoured, and the topsoil respread over 

the entire disturbed site to ensure successful revegetation.

8.5 Operation and Maintenance

8.5.1 Operational Procedures

a) Development of a standard operating procedure (SOP) manual applicable to each major facility should be 

considered. The SOP should contain information as to the equipment located at the facility, safe-operating 

practices for the equipment, start-up and shutdown procedures, and emergency procedures. 
ENVIRONMENTAL PROTECTION FOR ONSHORE OIL AND GAS PRODUCTION OPERATIONS AND LEASES 33

b) Consideration should be given to the analysis of failures or malfunctions so that corrective action can be taken to 

minimize future environmental incidents.

8.5.2 Personnel Training

Personnel should be trained in the safe and efficient use of facility equipment.

8.5.3 Equipment Inspection

Routine inspections should be considered on all equipment operating in corrosive environments. All safety 

equipment should be tested on a routine basis to ensure proper operation.

8.5.4 Corrosion Monitoring and Treatment

Monitoring should be considered if produced fluids are suspected of being corrosive. If produced fluids are 

determined to be corrosive, a corrosion abatement program should be considered. This is especially important in 

populated or environmentally sensitive areas. Operating procedures should provide for early identification of 

potential corrosion problems in failure-prone equipment. Refer to NACE MR 0175.

8.5.5 Housekeeping

a) The facilities should be kept clean, maintained, and operated in a safe and environmentally sound manner.

b) Facilities should be fenced in a manner to prevent access to the facility by the general public, livestock, or 

wildlife, where appropriate.

c) Signs should be posted in conspicuous locations to notify employees and the public of any dangerous situations 

such as, flammable conditions, high voltage, and hydrogen sulfide. State or local regulations may specify certain 

posting requirements.

d) Emergency phone numbers should be posted at the entrance to the facility, if located near a populated area.

e) Weeds should be controlled to a degree compatible with the local environment by cutting, mowing, or spraying to 

improve appearance and reduce the fire hazard. When herbicides are used to control weeds, the chemicals 

should be properly applied by trained personnel. 

f) All equipment should be painted and/or kept clean to present an acceptable appearance and to provide 

protection from external corrosion.

g) Waste receptacles should be provided at appropriate locations for collecting discarded paper, rags, etc. and 

emptied on a regular basis.
34 API RECOMMENDED PRACTICE 51R

8.6 Waste and Residual Management

8.6.1 General 

Waste and residual management practices for production operations should be conducted consistent with lease and 

landowner obligations. This should include solid wastes and residuals, such as tank bottoms, drilling fluids and 

cuttings, liquid wastes and residuals, such as produced water and used oil, and gaseous wastes, such as 

hydrocarbons and carbon dioxide. A sound waste management plan is important to protect human health and the 

environment and minimize long-term liabilities to the operator.

A waste or residual management plan should utilize one or all of the options listed below, in order of preference, to 

protect human health and the environment.

a) Source Reduction—Minimize or eliminate the volume and/or toxicity of the waste generated.

b) Recycling—Reclaim or reuse the maximum amount of waste possible.

c) Treatment—Utilize techniques to minimize the amount and the toxicity of waste after it is generated, thereby 

minimizing the amount that has to be disposed.

d) Disposal—Employ environmentally sound and approved methods to properly dispose of generated wastes.

8.6.2 Source Reduction

Source reduction involves decreasing the volume or toxicity of wastes or other residuals that are generated. Product 

substitution is an example of source reduction. Production and workover chemicals should be evaluated to 

determine if less toxic substitutes are available that meet the performance and economic criteria of the operator.

Reviewing common-sense housekeeping practices can be effective in reducing waste or other residual generation. 

Installing drip pans, as an example, on valves and fittings allows the collection of leaked oil before it contacts the soil 

and becomes a waste.

8.6.3 Recycling and Reclaiming

After all reduction options are considered, recycling or reclaiming the residual material should be evaluated. 

Examples of recycling and reclaiming are recovering waste oil, hydraulic oil, and oily sump water by reintroduction 

into the oil stream or transportation to a refinery. Drums, batteries, and scrap metal can be sold or returned to the 

vendor, where possible. Tank bottoms and sludges can be sold to reclaimers, where feasible.

8.6.4 Treatment

Following reduction and recycling efforts, treatment of waste should be considered to minimize the waste volume 

and the toxicity of the waste.
ENVIRONMENTAL PROTECTION FOR ONSHORE OIL AND GAS PRODUCTION OPERATIONS AND LEASES 35

Filtration, centrifugation, evaporation, and flocculation are examples of reduction techniques that can reduce the 

volume of the actual waste that must be disposed. The toxicity of certain wastes can be reduced by chemical 

treatment, thermal treatment, and biodegradation before disposal.

8.6.5 Disposal

The final option for management of a waste, after source reduction, recycling, and treatment options have been 

considered and incorporated, is disposal. The operator should take into consideration the long-term fate of the waste 

and its constituents before disposal. Considerations that should be evaluated when choosing either an on-site or an 

off-site commercial disposal method are as follows: 

a) general site review of the topographical and geologic features,

b) groundwater review to determine the presence of groundwater and aquifers,

c) area weather patterns to estimate rainfall and flooding potential,

d) general soil conditions,

e) natural drainage areas,

f) identification of environmentally sensitive conditions,

g) air quality.

These criteria will help determine a waste disposal option that protects human health and the environment and limits 

future liability for the operator. Examples of waste disposal options that can be considered are:

a) landspreading,

b) roadspreading,

c) on-site burial,

d) on-site pits,

e) annular injection,

f) underground injection wells,

g) regulated and permitted discharge of fluid,

h) incineration,

i) off-site commercial facility.
36 API RECOMMENDED PRACTICE 51R

The operator should maintain adequate documentation of waste management activities. Development of a long-term 

records retention policy should be considered.

Refer to API Environmental Guidance Document: Onshore Solid Waste Management in Exploration and Production 

Operations and API’s Guidelines for Commercial Exploration and Production Waste Management Facilities.

8.7 Spill Prevention, Response, and Cleanup

8.7.1 General

Accidental spills (including oil and saltwater) can, besides potentially damaging the environment, create difficult 

operational, legal, and public relations problems. It is very important to conduct operations in a manner that 

minimizes the potential for unauthorized spills. Spill prevention, response, and cleanup procedures should be 

defined and in place before storing any oil or chemicals on site or conducting activities that have a potential for a 

spill. Outlined hereunder are some recommended operating practices which can be implemented by operators to 

minimize waste volumes and impacts on the environment.

8.7.2 Prevention

The best way to avoid adverse effects of spills is to prevent their occurrence. The key factors in spill incident 

prevention are adequately trained supervisors and field operating personnel. The following basic steps can be taken 

to prevent accidental spills.

a) The facility design should be reviewed to determine where the potential for spills exists. Information on prior spill 

incidents should be included in the review to assess areas where changes in equipment or practices may be 

needed. Using the results of the review, the following should be considered, as appropriate.

1) Modification of existing facilities or installation of new equipment or instrumentation, as needed, to reduce the 

possibility of spills, commensurate with the risk involved. Consideration should be given to the use of alarms, 

automatic shutdown equipment, or fail-safe equipment to prevent, control, or minimize potential spills resulting 

from equipment failure or human error.

2) Maintenance and/or corrosion abatement programs to provide for continued adequacy of all equipment.

3) Routinely scheduled tests and inspections of lines, vessels, dump valves, hoses, and other pollution 

prevention equipment where failure(s) and/or malfunction(s) could result in a potential spill incident. These 

tests and inspections should be commensurate with the complexity, conditions, and circumstances of the 

facility.

4) Operating procedures that minimize potential spills. These operating procedures should be clearly written and 

available to all operating personnel.

5) Examination of field drainage patterns and construction of oil traps in drainage ditches at strategic points to 

contain spilled oil before it reaches streams or water basins. 

b) Training programs should be developed on spill prevention fundamentals and presented to operating personnel 

as often as necessary to keep them well versed on spill prevention practices. 
ENVIRONMENTAL PROTECTION FOR ONSHORE OIL AND GAS PRODUCTION OPERATIONS AND LEASES 37

c) Contingency and shutdown plans should be developed for coping with hurricanes and other disasters (both 

natural and manmade) so as to minimize the potential for oil spills or incidents causing pollution or other 

environmental damage.

8.7.3 Mitigation

Some other associated steps that should be taken to reduce the potential for oil spills are: 

a) “dead” piping and temporary connections should be removed when they are no longer required;

b) piping subject to vibration should be braced to reduce movement and resulting fatigue failures;

c) tanks should be checked for uneven settlement of the foundation, corrosion, and leaks;

d) installation of pressure relief valves should be considered for liquid lines, which, if left full, could potentially 

rupture from liquid expansion due to heat;

e) sleeve-type line couplings should not be used when there is a chance of line movement.

8.7.4 Spill Contingency Plan

In the event a spill occurs, it is extremely important for all responsible operating personnel to know how to respond 

quickly and effectively to control, contain, and clean up the spill. To ensure this capacity exists, a contingency plan 

should be prepared for inland areas as well as for areas near water. The plans should provide utilization of 

capabilities of oil spill cooperatives, whenever advantageous.

Spill plans should address the needs to advise the public about significant releases. The plan should include 

procedures to advise government officials and provide appropriate information and access to the press.

8.7.5 Control and Containment

In the event a spill occurs, the source of the spill should be stopped, or reduced as much as possible, in a safe 

manner. The spread of the spilled substance should be controlled or contained in the smallest possible area to 

minimize the adverse effects. Some methods which can be used to control and contain discharged substances, 

particularly oil, include:

a) retaining walls or dikes around tanks and other spill prone equipment,

b) secondary catchment basins designed to prevent the spread of oil if it escapes the primary wall or dike,

c) permanent booms in water basins adjoining the facility,

d) temporary booms deployed in the water after the spill occurs,

e) use of special chemicals to jell or biodegrade the oil to prevent the spread of oil spilled into or on water.
38 API RECOMMENDED PRACTICE 51R

Operators should evaluate the potential for spills and damages and use this information to determine the type and 

size of primary and secondary containment necessary.

The type and footage of containment boom installed or stored for deployment will vary with the type, size, and 

location of the facility and spill potential. This information should be developed for each main area or facility and be 

stated in the facility contingency plan. In addition, the contingency plan should list where emergency equipment is 

located.

The contingency plan should state the type(s) of chemicals that can be used effectively and list sources and 

procedures for applying these chemicals. Spill response drills/simulations should be considered, with regulatory 

agency and contractor personnel participating.

8.7.6 Cleanup

Cleanup procedures should be developed and included in the facility contingency plan. Up-to-date lists of effective 

cleanup materials and equipment and a list of potential contractors who can supply needed assistance should also 

be included and maintained in the contingency plan.

Depending on the spill potential at each area, a stock of appropriate cleanup materials sufficient to handle small 

spills should be maintained on hand at all times. The amount of cleanup material will depend on the time required to 

obtain more material if the size of the spill should increase.

The following suggested cleanup practices should be considered.

a) Using cleanup materials and equipment on hand, immediate action should be taken to clean up any spilled oil or 

other substance. Depending on the substance spilled, personnel performing and supervising cleanup operations 

may require specific training. 

b) Advance planning and arrangements should include availability and ready access to vacuum trucks and to 

similar pickup equipment to recover the spilled material.

c) Necessary approvals should be obtained before disposal of spill cleanup materials.

d) Advance arrangements should be made for rights of ingress and egress to public and private property that may 

be affected by a spill or the ensuing cleanup operation.

e) Landowners should also be notified of spills and kept informed of spill cleanup progress.

f) Plans, procedures, and programs should be improved and updated by analyzing previous spill incidents. 

Prevention, control and containment, and cleanup procedures should be revised accordingly to make them more 

effective for future responses.

8.8 Environmental Assessment Before Purchase or Sale of Existing Fields and Leases

Before the purchase or sale of an existing field or lease, consideration should be given to documenting the 

environmental condition of that property. By documenting the presence or absence of surface, subsurface, or 
ENVIRONMENTAL PROTECTION FOR ONSHORE OIL AND GAS PRODUCTION OPERATIONS AND LEASES 39

groundwater contamination, an operating company may be able to reduce its exposure to significant future liabilities. 

Aerial photographs may be beneficial during this process.

Documentation of audits, assessments, and operating practices is important to identify potential problem areas. 

Care should be taken to document actions taken to correct deficiencies identified by audits.

8.9 Closure and Abandonment of Facilities

8.9.1 Purging and Flushing of Equipment Before Removal

All equipment such as tankage, separation vessels, meter runs, flow lines, and pumps should be purged and 

flushed, as appropriate. Whenever possible, materials recovered should be recycled, reclaimed, or disposed. Refer 

to API Environmental Guidance Document: Onshore Solid Waste Management in Exploration and Production 

Operations for additional information.

8.9.2 Equipment Removal

The following equipment removal issues should be considered.

a) Tanks, separation vessels, meter runs, surface lines, pumps, and any other exposed surface equipment should 

be removed. Removal of the associated equipment foundations should be considered.

b) Exposed piping segments from surface or subsurface equipment connecting to buried lines should be removed 

to a depth consistent with subsequent land use or, preferably, to the depth of buried lines. Where feasible or 

where desired to limit potential future liabilities, consideration should be given to removing buried lines.

c) Where appropriate, each outlet of any abandoned lines should be permanently sealed.

d) Operators should consider removing all crossing markers and other line markers.

e) Where appropriate, the location of abandoned lines should be identified on facility maps.

8.9.3 Pit Closure

All pits and surface impoundments should be properly closed after they are dry and free of waste; then they should 

be backfilled and graded to conform to the surrounding terrain. Closure must also be in accordance with any local 

and/or state regulations. The location of closed pits should be documented. Materials removed from pits should be 

reclaimed, recycled or disposed. Refer to API Environmental Guidance Document: Onshore Solid Waste 

Management in Exploration and Production Operations for additional information. Documentation should be kept on 

disposed materials.

8.9.4 Land Reclamation and Restoration

Upon completion of abandonment activities, all disturbed surface areas should be cleaned up and restored to 

conditions similar to the adjacent land or to landowner requirements.
40 API RECOMMENDED PRACTICE 51R

Timely completion of final reclamation is as important as the initial planning. Incomplete or improperly executed final 

reclamation can result in the complete loss of a low-impact project opportunity. Reclamation becomes significantly 

more difficult, more expensive, and less effective if sufficient topsoil is not salvaged, interim reclamation is not 

completed, and if proper care is not taken to construct pads and roads in locations that minimize reclamation costs.

Revegetation alone does not constitute successful reclamation. Restoration of the original landform is a key element 

in ensuring that the effects of oil and gas development are not permanent.

To achieve final reclamation of a recently drilled dry hole, the well site should be recontoured to original contour or to 

a contour that blends with the surrounding landform, stockpiled topsoil redistributed, and the site revegetated. To 

achieve final reclamation of a formerly producing well, all topsoil and vegetation must be restriped from all portions of 

the old well site that were not previously reshaped to blend with the contour of the surrounding landform. All 

disturbed areas are then recontoured back to the original contour or a contour that blends with the surrounding 

landform, topsoil is redistributed, and the site revegetated, using native plant species or agency approved seed 

mixes using native plant species or agency approved seed mixes “that are acceptable to the landowner or trustee.

In recontouring areas that have been surfaced with gravel or similar materials, the material should be removed from 

the well location or buried deep in the recontoured cut to prevent possible surface exposure. 

Infrastructure associated with formerly producing leases, including water impoundments, power lines, metering 

buildings, compression facilities and tank batteries must be removed and the footprints or lands disturbed by these 

facilities and associated foundations reclaimed unless the surface owner requests that items such as impoundments 

or water wells be kept.

Salvaged topsoil should be respread evenly over the surfaces to be revegetated. The topsoiled site should be 

prepared to provide a seedbed for reestablishment of desirable vegetation. Site preparation may include gouging, 

scarifying, dozer track-walking, mulching, fertilizing, seeding and planting. In reclamation of sites that are not 

cultivated for agriculture or grazing, seeding and planting should use plant species indigenous to the area.

Water breaks and terracing should only be installed when absolutely necessary to prevent erosion of fill material and 

should be removed when the site is successfully revegetated and stabilized.
ENVIRONMENTAL PROTECTION FOR ONSHORE OIL AND GAS PRODUCTION OPERATIONS AND LEASES 41

Annex A

Good Neighbor Guidelines

(This annex provides guidance for a company to consider as it manages its relationships with surface users, 

communities and others in areas where it operates.) 

The oil and natural gas industry is dedicated to responsible development of oil and natural gas resources. 

Responsible development includes good relationships with our neighbors and a commitment to environmental 

protection and compliance with all applicable federal, state, and local regulations.

To be a “good neighbor” in the areas where industry operates, we have three objectives:

— protection of public safety;

— protection of the environment; and

— respect for the property rights of others.

These objectives are achieved through use of sound management processes as part of the responsibility to act as a 

“good neighbor.” As our industry pursues responsible development of energy resources to meet the nation’s energy 

needs, we should strive for better communication and understanding with the land owners, lessees, permittees 

and/or residents (“land owner or surface users”) impacted by our operations.

Good Neighbor Practices

Listen to the land owner or surface user concerns and respond appropriately:

— respect rights-of-way,

— take precautions to protect livestock,

— take precautions not to harm wildlife with our operations,

— drive safely,

— report damages to public or private property to the appropriate parties,

— maintain production equipment and systems, and

— train personnel on the rules and regulations applicable to our operations.

Communicate with land owners and surface users:

— be willing to discuss with the land owner or surface user of industry property use rights (including mineral rights) 

and surface use rights,
42 API RECOMMENDED PRACTICE 51R

— designate a company contact person who is responsible for responding to community questions,

— listen to and discuss the concerns of the land owner or surface user affected by our operations, and

— attempt to notify the landowner or surface user when commencing significant activity that will impact their land.

Respect the property and the rights of others:

— minimize surface disturbances,

— take precautions to protect livestock with appropriate measures,

— practice good housekeeping,

— remediate and restore the site in a timely manner in compliance with applicable regulations, and

— drive responsibly on public and private roads.

Promote safety of the general public:

— train personnel in safe operating practices,

— conduct emergency planning where applicable, and

— post signage and warnings in accordance with regulations.

Protect the environment:

— train personnel on environmental protection in compliance with applicable regulations; and

— maintain equipment and utilize good work practices;

— seek to understand the land owner, and surface user concerns and possible questions regarding:

— groundwater aquifers and surface water,

— air quality,

— wildlife and livestock protection,

— housekeeping,

— noise,

— surface disturbance, and

— noxious weeds and brush;

— follow regulations for waste management and environmental protection.