Pits

At a drilling site pits are used to store water, contain drilling fluids and cuttings or to hold other liquid substances such as brine or oil. Sites we’ve examined have all had at least one pit, that for drilling fluids and cuttings. These pits may also have held used fracture fluids (flowback). The only sites that probably didn’t have a pit were those dating from the 1940s.

Unless an examination is made of a number of Discharge Monitoring Reports filed with the state we have no way of knowing what percentage of pits may possibly have held flowback (category 1 pits do not contain flowback). Because of that we have to assume all pits contain some flowback.

Regulation of pits and what they can hold is distributed over three platforms in West Virginia: code of state regulations (35 CSR 4.16.4), Erosion and Sedimentation Control Field Manual (II.B.2 and III.A) and General Water Pollution Control Permit (G2, G10 and G15). This is typical for this state where regulatory control is dispersed and lacks any form of quantification. For example, freeboard is required by the code of state regulations (35 CSR 4.16.4c), but no amount of required freeboard is given, such as 2 feet. Other absences include no limitation of placement in respect to ground or surface water. A driller, in essence, can put a pit anywhere, even where common sense would dictate differently.

We’ve created a webpage that has the three regulatory platforms’ texts together in one spot.

Problems with the state’s regulations occur in these areas: no limitation of pit location in respect to ground water; no limitation of placement of pit on site (fill area) or near surface water; no specifications for proper liner and installation/welding; no technique for proper encapsulation of solid waste and cover requirements; and finally, no placement of permanent marker and filing a deed notice to comply with Federal Housing Administration requirements for future builders and homeowners. Except for possibly the last item, the state’s policies do not protect the environment or the health and welfare of its citizens.

Ground Water
While the state’s regulations make offhand requirements to protect the state’s waters, there is no minimum distance between the bottom of the pit and ground water. The Argonne National Laboratory recommends a minimum of 5 feet between the bottom of the pit and seasonal high water level. British Columbia requires a minimum of 1 meter. New Mexico in its recently updated regulations requires the distance be at least 50 feet. We believe the state should adopt the Argonne National Laboratory’s recommendation at a minimum. The distance should be much more in sandy soils.

Pit Location
The pit needs to be placed in firm soil. Sandy soils are not appropriate without amendment of some sort according to the Railroad Commission of Texas. Fill soils are inappropriate and pits in fill soils need special written permission in British Columbia. Placing a pit on the edge of the pad by the fill slope is not recommended by the Erosion and Sedimentation Control Field Manual but we believe this is quite common. With pits increasing dramatically in size, the state needs to regulate or somehow control the use of fill soils.

The pit needs to have the site constructed so that rain or other water is directed away from the pit (with berm and/or ditch). The General Water Pollution Control Permit actually sanctions the directing of stormwater into the pit (G15). Overflow of the pit because of improper stormwater drainage causes contamination of soils, ground and surface water. The freeboard needs to be a stated amount (New Mexico and Arkansas require 2 feet freeboard).

The location of a pit near a body of surface water should be regulated. New Mexico requires a distance of 300 feet from a river (other setbacks are regulated in New Mexico, such as 500 feet from a domestic water source). In Texas, water wells within 1 mile of a pit need to be recorded in the permit, as does the depth of the shallowest freshwater for those wells. Arkansas has similar requirements in its permit for landspraying.

Pit Liners
Pit liners are optional for this state but I believe are commonly used. Liners should always be required. The state has no specifications for liners which are available in a variety of materials and thicknesses. The state also has no requirements for locations of seams (up and down slopes, not laterally, for instance) or installation (type and depth of anchor trench). We believe that New Mexico’s regulations could easily be adapted.

Burial and Cover
Before burial, the solids at the bottom of the pit are encapsulated (though West Virginia doesn’t require encapsulation; open liners and contents can be buried shallowly). Basically, encapsulation means the pit liner’s edges are folded over the solids preventing their escape. Cover over the burial cell is important since enough depth is required to prevent plant roots from disturbing the liner’s integrity. The Argonne National Laboratory recommends at least 3 feet of cover. We believe that more is required where the reclaimed surface will eventually revert to forest. Soil cover needs to be graded so that the surface doesn’t allow the ponding of water. We believe the Argonne National Laboratory’s recommendations should be incorporated in the state’s regulations.

Permanent Marker
There needs to be a way to record the exact location of each pit in the state. In New Mexico this is done through a deed notice associated with the surface owner’s property deed. New Mexico also requires a permanent marker much like that required in this state for plugged wells — a steel monument 3 feet above the ground’s surface. British Columbia requires a separate pit permit and registration for each pit and the pit number(s) posted at the drill site (Arkansas has similar requirements). New Mexico’s regulations were written so as to not disadvantage surface owners at the present or in the future because of Federal Housing Administration requirements. This state needs to do the same.

In a future post we’ll present our recommendations for pits adapted from our comments for Raymond City #17.

Sources:

Argonne National Laboratory. Fact Sheet – Onsite Burial (Pits, Landfills). Drilling Waste Management, web page accessed 20 September 2008.

Arkansas. 2008. Authorization to Construct, Operate and Close the Pits Associated with Oil and Gas Well Exploration. Arkansas Department of Environmental Quality, Permit No. 00000-WG-P.

British Columbia Oil and Gas Commission. n.d. British Columbia Oil and Gas Handbook, Chapter 10, Drilling Waste Management. n.p.: British Columbia Oil and Gas Commission.

Department of Housing and Urban Development. 1999. Changes to Handbook 4150.2, Valuation Analysis for Single Family One- to Four-Unit Dwellings. n.p.: Department of Housing and Urban Development. Chapter 2: Site Analysis, 2.2.E.

New Mexico. 2008. New Mexico Code and State Rules for Oil and Gas. New Mexico Energy, Minerals and Natural Resources Department, Oil Conservation Division.

New Mexico. Highlights of the “Pit Rule” — 19.15.17 NMAC. Santa Fe, NM: New Mexico Energy, Minerals and Natural Resources Department, Oil Conservation Division.

Railroad Commission of Texas. Surface Waste Management Manual, Chapter 4, Pits. Railroad Commission of Texas website, accessed 8 December 2008.

April 28, 2009