We’ll be referring to the table we have available for download for the screening levels for assessment.

For this state, assessment of soil contamination proceeds in a systematic manner (see the Decision Tree document). The sample’s concentration is compared to background levels — either uncontaminated soil from or near the site or state background levels. If the sample’s concentration is lower than the background level, then there is no problem. If the concentration is higher then the next stage of assessment is made. For our samples, arsenic and lead were higher than the maximum concentrations in the state’s background levels. Barium and chromium were lower so those metals aren’t considered a concern. (Canada is currently creating national guidelines for acceptable concentrations of chemicals in soil. These limitations will be in force, even if the soil background concentration is higher.)

The next step is to compare arsenic and lead concentrations to the soil to groundwater screening levels. The EPA recently changed their screening levels (June 2009) and we’re using the EPA’s current screening levels for this region. The sample’s concentrations for lead and arsenic were both higher than the soil to groundwater screening levels (arsenic is also higher for the state’s soil to groundwater screening level — these for some reason are about 20 times higher than the EPA’s). Typically this means that groundwater needs to be tested for these elements.

The next step is to consider residential screening levels. In this case, the arsenic concentration is still higher than the residential screening level, but lead is lower.

In West Virginia an option where soil screening levels are high for residential but don’t exceed the industrial soil screening level, is a deed restriction, so that the property can only be used for industrial activity and not as a place to live, garden or farm. We don’t believe that is an option here since the well pad is on a half acre of a much larger piece of property. The natural gas operator doesn’t own the property, they lease the mineral rights from someone else who owns the mineral rights. Surface rights were severed from the mineral rights some time ago.

Another concern for all the metals — arsenic, barium, chromium and lead — is how much higher their concentrations are than ecological screening levels. In the case of arsenic the eco-ssl is much higher than the residential soil screening level (but the sample’s concentration is higher still), while for barium, chromium and lead the eco-ssl are much lower than residential screening levels.

Our preliminary assessment comes from the laboratory analysis of one spot within an affected surface area of at least 1500 square feet. The matrix has a high chloride concentration which would enable the transport of chemicals through soil to water beyond the confines of the site. It’s entirely possible that laboratory analysis at other points would alter the preliminary assessment’s chemicals of concern and add others. It’s also possible that the pit liner is no longer intact at the bottom further north of the sample location and migration of pollutants has already occurred.

For these reasons, we believe the site deserves a full assessment by a professional though we believe that remediation options for the operator are limited. We hesitate to make recommendations but believe the operator’s preference of doing nothing is not viable because we believe that the site’s unremediated presence is a danger to those living nearby.

This is a follow-up post to The Numbers where we provided laboratory analysis results for a sample of pit waste at a natural gas well site. Risk assessment is a huge topic so we’ll be splitting the post into two parts. In this part we’ll discuss some features of the site that have to be taken into consideration and use information on a table we’ve created with various screening levels and other information for the chemicals analyzed by the laboratory in the sample.

We’re not doing a full assessment of the site; what we’re doing is trying to find is out if a full assessment toward remediation is necessary.

The state’s DEP Office of Environmental Remediation has several publications that have been helpful to us. These are all associated with their program of voluntary remediation. A Plain Language Guide to Human Health Risk Assessment is a description of the process of analysis and decision-making. There is a helpful checklist at the end which is taken from Appendix A of West Virginia Voluntary Remediation and Redevelopment Act Guidance Manual which is a much more technical document written for remediation specialists. The third element in the publication mix is the De Minimis tables which are part of 60 Code of State Regulations 3. These tables provide screening levels for a large number of chemicals. (The state’s and EPA’s tables use exponents such as E-01 or E+02 with concentration, e.g., 3.89E-01. E-01 is equal to X 10^-1 and E+02 is equal to X 10². For the example 3.89E-01, the concentration is then 0.389. We find this method of presentation to be a pain and much prefer either a uniform parts per billion presentation or as we’ve presented the figures in our table. A scientific calculator will easily convert positive and negative exponents.)

When we had analysis done we just asked for metals, chloride and radium 226 and radium 228. Chloride doesn’t have a screening level, in spite of the fact that there is a secondary Maximum Contaminant Level for drinking water for chloride and in spite of the fact that chloride can be toxic to aquatic life, birds and mammals. Radiological screening levels are a whole other topic and since the radium in the sample was at an acceptable concentration we’ve put that aside.

Three of the metals that we had analyzed, even though they show high concentrations, are not considered important in an environmental assessment — calcium, magnesium and sodium. In the end, the assessment has to focus on arsenic, barium, chromium and lead (cadmium was not able to be detected by the laboratory), though we believe the high chloride is an important factor.

The site is a gas well drilled in 2005 to the Marcellus formation but two other shales were also fractured. Copies of the well completion report and plat are available for download. The well has a pad of about 100 by 200 feet with a drop off to the north where there’s a steep slope into a hollow. On a flat below the well is a spring-fed cistern (about 326 feet from the well according to our GPS). The pit is between the wellhead and the drop off and is partially in fill soil.

This is on the same ridge (but a mile north of us) that we live on and we have seasonally high groundwater in winter and spring with two ephemeral springs close to the house. It’s possible that the site we’re examining also has a perched aquifer with groundwater close to the surface. Some our neighbors, until this year when city water came to the ridge, depended on spring-fed cisterns (like the one below the well site), all at about the same elevation but in different areas, and it’s believed they all are fed by the same aquifer. I don’t know if everyone has city water now or if some still depend on spring-fed cisterns. The family with the cistern below the well site intended to use that cistern for a vegetable garden — their drinking water comes from a shallow well fed by a deeper aquifer. It’s possible that these aquifers are connected.

The photographs in The Numbers post give an idea of what we saw. The area bare of vegetation — the hot spot — is also the lowest spot on the site and has ponding water.

The well pad is next to a state road with a house opposite. That house is about 200 feet from the well and pit area and has a vegetable garden alongside the road. Since there is a residence so close to the site and since we believe that it’s possible that the pad area might be used as a building lot once the well structures are gone, we’ve considered this a residential site.

We’re also concerned about the ecological effects that the metals and chloride would have on vegetation and wildlife. We’ve seen plenty of deer tracks in the hot spot on the surface and assume that deer are attracted to the salts and minerals. In our assessment, since deer are hunted and eaten in this area, we have a possible crossover with not just ecological assessment concerns but also human risk concerns.

We’ll be doing a soil assessment and the factors we’ll be considering include what the sample metals concentrations are, what the typical background soil concentrations are in this state and then the various screening levels. That will be discussed in the second part. Here’s that link again to the risk assessment table we’ve created for this site.

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.