This is an examination of the chemicals used in drilling and found in waste, and their management.

Pits
   Pit Liners
   Pits
   Current state regulations
   Recommendations for change

Drilling Waste Management
  What Happened at Fernow
  The Spill at Buckeye Creek

The Gas Well Study

Reclamation

The Old Well

Draft Recommendations for Pit Regulations

Notes:
Siting Section distances (2.001-2.005) are suggestions only offered to encourage debate on this topic. Just how close should a pit be to dwellings and water? Soil consideration is mentioned in 2.005 but just how specific and what special soils require special regulation is open for discussion.

3.1 Temporary and Permananent Pit Construction are based on distinctions in New Mexico's pit regulations. I wonder if large volume pits (5,000 barrels or more) shouldn't have stricter lining requirements even though they are temporary pits -- say 30 HDPE single liner.

Testing criteria in 5.003 is for pit solids. It's assumed that if liquids for landspraying meet requirements, then solids will also. For pits with liquids not disposed of by landspraynig, testing probably should meet major criteria for landspraying: chlorides, metals and hydrocarbons/organics. One way to write this requirement in 5.003 would be to use same testing as for landspraying. Since there is no current valid landspraying criteria for this state (the state's current criteria are open to serious criticism) I've offered what's shown here. Again, this provides a point for discussion.

1 Special Permit

1. 001 A permit is required for each pit. A pit permit can be part of an application to drill or be made separately. A pit permit is not a disposal permit by land application (landspraying) which is a separate permit. A general permit cannot be used for pits holding over 5,000 barrels.

1.002 A pit must be constructed, maintained, and closed according to the principles in this permit or alternative principles allowed by the Office. In either case, the pit permit application must be prepared by a professional engineer.

1.003 Operating and maintenance procedures in the permit are minimum acceptable standards.

1.004 The closure plan must include details of how pit contents are to be disposed. Landspraying requires a separate permit.

1.005 Hydrogeologic data must be provided for each pit application. This data includes maps for soil and surface and ground water described in 2 Siting.

1.006 The size of the pit (length and width) in addition to the fluid depth is required for a pit permit.

1.007 The exact location of the pit's centerpoint is required (longitude and latitude).

1.008 Pit's use must be indicated in the permit, whether for water storage, freshwater mud, oil-based mud, produced water/oil, etc.

1.009 A pit whose contents are to be landsprayed cannot receive fracturing flowback or unused fracturing acid or materials.

2. Siting

2.001 A pit can be no closer than 500 feet to a building used by persons, such as a dwelling or business. Note that border of land application, if permitted as a disposal option, must also be at least 500 feet from a dwelling or business.

2.002 A pit can be no closer than 500 feet from a building used by groups of persons such as a church, school or large business/factory. Land application area border, in this instance, must be at least 1,000 feet from such a building.

2.003 A pit can be no closer than 300 feet from perennial and intermittent streams and rivers, lakes or ponds (as indicated on U.S. Geological Survey 7.5 quadrangle).

2.004 A pit can be no closer than 150 feet from ephemeral and intermittent streams not shown on 7.5 quadrangle but appearing in hydrogeologic survey.

2.005 A pit can be no closer than 500 feet from a wetland (as appearing on 7.5 quadrangle).

2.006 A pit can be no closer than 500 feet from a private domestic water source (used by 5 families or less), whether well or spring. A pit can be no closer than 1,000 feet from other drinking water sources (6 families or more), except in the case of municipal water source.

2.007 A pit can be no closer than 2,500 feet from a municipal water source, whether it be a wellfield or surface water body.

2.008 A pit's bottom can be no closer than 15 feet from the seasonally high water table. In certain soils, such as karst, the distance is 50 feet, and a specially engineered pit with 40 mil HDPE liner or better is required.

2.009 Pit application will include the following maps:

2.0091 Detail of location on 7.5 quadrangle showing contour lines.

2.0092 Map of 1 mile radius indicating intermittent and perennial streams and rivers, lakes and ponds, and ephemeral streams and wetlands. Also indicated on this map will be locations of all domestic and municipal water sources and depth of ground water.

2.0093 Soil map from the National Resource Conservation Service showing location of pit and, if applicable, land application area.

3 General Pit Design and Construction

3.001 Topsoil will be saved during pit construction to be used as final cover during reclamation.

3.002 Each pit will have a sign indicating Office assigned pit number, well name and API number, operator name and emergency numbers for operator and Office. The sign will also include the location (longitude and latitude).

3.003 Each pit will be fenced with a substantial fence to prevent access by persons and wildlife to the pit.

3.1 Temporary Pit and Permanent Pit Construction

3.101 A pit can only be constructed in undisturbed soil. A pit that is to be constructed in fill soil or on edge of fill slope must have specifications for construction prepared by professional engineer and approval in writing by the Office. A pit which will hold 5,000 barrels or more will not be exempted.

3.102 Pit slope will be no steeper than 2:1 (2rise:1run).

3.103 The excavated surface for the pit will be as smooth as possible with no rocks, tree limbs or roots, that can pierce the lining. It may be necessary to use sand or geotextile as underlayment for liner.

3.104 Excavated pit will have surface compacted by roller or other means before liner is installed.

3.105 A temporary pit means a pit, including a drilling or workover pit, which is constructed with the intent that the pit will hold liquids for less than 6 months and will be closed in less than 1 year.

3.2 Pit Liner

3.201 All pits will be lined with an appropriate liner or better.

3.202 Liner for temporary pit will be geomembrane liner 20-mil string reinforced LLDPE or equivalent material (impervious synthetic material that is resistant to petroleum hydrocarbons, salts and acidic and alkaline solutions and resistant to ultraviolet light). Liner compatibility will comply with EPA SW-846 method 9090A.

3.203 Liner for permanent pit two liners with leak detection system (leak detection system and requirements for welding seams described below). The liners to be 30-mil flexible PVC or 60-mil HDPE or equivalent. The liner should have a hydraulic conductivity no greater than 1x10-9 cm/sec. The impervious synthetic material will be resistant to petroleum hydrocarbons, salts and acidic and alkaline solutions and also be resistant to ultraviolet light. Liner compatibility will comply with EPA SW-846 method 9090A. The operator will place a leak detection system between the upper and lower geomembrane liners that consists of two feet of compacted soil with a saturated hydraulic conductivity of 1 x 10-5 cm/sec or greater to facilitate drainage. The leak detection system will consist of a properly designed drainage and collection and removal system placed above the lower geomembrane liner in depressions and sloped to facilitate the earliest possible leak detection. Piping used will be designed to withstand chemical attack from oil field waste or leachate; structural loading from stresses and disturbances from overlying oil field waste, cover materials, equipment operation or expansion or contraction; and to facilitate clean-out maintenance. The material the operator places between the pipes and laterals will be sufficiently permeable to allow the transport of fluids to the drainage pipe. The slope of the interior sub-grade and of drainage lines and laterals will be at least a two percent grade, i.e., two feet vertical drop per 100 horizontal feet. The piping collection system will be comprised of solid and perforated pipe having a minimum diameter of four inches and a minimum wall thickness of schedule 80. The operator will seal a solid sidewall riser pipe to convey collected fluids to a collection, observation and disposal system located outside the permanent pit's perimeter. The operator may install alternative methods that the Office approves.

3.204 Liner seams will traverse pit slopes, up and down, rather than along slope. No seam will be within and along 5 feet of toe of slope.

3.205 Liner seams will be wedge welded with 6 inch overlap with dual seams for testing. The operator will test a seam by establishing an air pressure between 33 and 37 psi in the pocket and monitoring that the pressure does not change by more than one percent during five minutes after the pressure source is shut off from the pocket. Alternative standard for steam testing is current ASTM D 5820 (Standard Practice for Pressurized Air Channel Evaluation of Dual Seamed Geomembranes). Prior to field seaming, the operator will overlap liners six inches and orient seams parallel to the line of maximum slope, i.e., oriented across, not along, the slope. The operator will minimize the number of field seams in corners and irregularly shaped areas. Qualified personnel will perform field seaming. Pit will not be used unless all seams pass testing.

3.206 Liner will be anchored in an 18 inch deep v-shaped trench, filling trench entirely before compacted soil is used as anchor.

3.207 Pit wall bank (or levee) must be at least 24 inches between inner edge of anchor and pit slope.

3.208 Drawings showing proper welded seam and anchor trench details may be downloaded from Office website.

3.3 Stormwater

3.301 Stormwater and other water from the surface of the pad or environs must be kept from the pit.

3.302 Pit must have 2 feet freeboard at all times.

3.303 The V-shaped trench for anchoring the liner is not to be used as the ditch to keep stormwater from the pit. The bank (or levee) for a pit can act as a berm to prevent stormwater access to the pit, but a ditch is also required.

4. Operational Requirements

4.001 A pit with less than 2,500 barrels must be inspected at least once a week with an additional inspection immediately after a major storm or rain event (1 inch of rain or more).

4.002 A pit with 2,500 barrels to 4,999 barrels must be inspected at least twice a week with an addition inspection immediately after a major storm or rain event (1 inch of rain or more).

4.003 Pits with more than 5,000 barrels must be inspected once a day.

4.004 Inspections are to take place while pits have fluid. Pits with fluid removed, before closure, must be inspected once a week.

4.005 Office must be notified immediately when pit structure is damaged or breached or liner is broken.

4.006 Office must be notified within 5 days if there's been wildlife death.

4.007 If inspection determines inadequate freeboard, an emergency, temporary, pit may be constructed. See 6 Emergency Pits

4.008 If inspection determines instability of pit walls or structure or damage to liner, the office will be contacted in 24 hours with engineering proposal to repair instability or intent to repair liner. Freeboard must be maintained at all times.

5 Closure

5.001 Closure of pit will take place within 3 months of drill rig leaving site, or otherwise required by Office.

5.002 Closure will take place after fluids have been removed from pit.

5.003 If pit was used for other than freshwater mud or water storage, solids in pit, before burial, will meet the following maximum concentrations:

5.004 Closure entails either removal of solids and liner for proper disposal elsewhere or, when pit meets landspraying permit requirements or requirements in 5.003 above, burial of solids.

5.005 If solids are to remain in pit, they are to be enclosed in liner as a wrapped cell and another element of appropriate geomembrane liner will be used to cover the cell.

5.006 Cell is to be buried with at least 3 feet of cover, 4 feet if area is expected to revert to forest.

5.007 After closure, topsoil is reapplied and surface given a final grading so that it is contoured to shed water. Surface ponding is unacceptable.

5.008 Permanent seed must achieve 70% coverage (70% of previous coverage; forest is considered 100%) within 24 months. Reseeding and/or nutrient support will be required until site meets 70% standard.

5.1 Marker

5.101 A pit with encapsulated cell must have a permanent marker. The marker will be a steel pipe, set in cement 3 feet below the surface, extending 3 feet above the surface with the well's API number and pit number permanently affixed so that these numbers are easily seen. The marker will be set in the center of the pit, the geographic location noted on the permit application.

5.102 A deed notice for the location of the pit will be recorded in the appropriate county or counties' deed office, associating the pit, with its location, and the deed of the surface or property owner.

6 Emergency Pit

6.001 An emergency pit, after notice is given to the Office, can be constructed without a permit.

6.002 The purpose of the emergency pit will be to provide temporary freeboard to permitted pit, whether in the case of an unusual storm event or failure of all or part of the permitted pits' structure or liner.

6.003 An emergency pit is temporary and, if unlined, contaminated soil must be disposed of properly off site. Soil disposal will not be required in the case of a fresh water storage pit.