October 1, 2011

Drilling and natural hazards: meet NORM

I mostly enjoyed the first 35 pages of the hydrofracking SGEIS chapter on geology. Then I hit page 4-35. It rapidly became clear that while there's some information where the oil and gas companies' approach - and apparently that of the geologists the DEC hired - has some serious limitations. There's not that much controversial to questions like where the gas might be hiding or what seismic activity there is in this part of New York.

Unfortunately, the last two sections of the geology chapter are about risks of drilling, and don't really convince me that the DEC knows that much about what's down there.

Section 4.6 is "Naturally Occurring Radioactive Materials (NORM) in Marcellus Shale". The key piece of information it reports is that:

The Marcellus is known to contain concentrations of NORM such as uranium-238 and radium-226 at higher levels than surrounding rock formations.

Section reports on tests of Marcellus samples from New York and Pennsylvania, concluding that:

"the results, which indicate levels of radioactivity that are essentially equal to background values, do not indicate an exposure concern for workers or the general public associated with Marcellus cuttings."

This leaves me wondering whether radiation conditions at the surface are higher than they are in most rock formations except the Marcellus.

Both of these sections, though, left me with a basic question: does the Utica Shale have similar radiation issues? It seems like someone must have tested it, and omitting that from a document which claims to be laying the groundwork for both Marcellus and Utica Shale exploration seems like a bad idea.

The next section, 5.2.5, discusses containing those cuttings and drilling fluids at the site.

Section 6.7, "Naturally Occurring Radioactive Materials in the Marcellus Shale", explains more about the challenges that do come with that radiation:

Gas wells can bring NORM to the surface in the cuttings, flowback fluid and production brine, and NORM can accumulate in pipes and tanks (pipe scale and sludge.) Based upon currently available information it is anticipated that flowback water will not contain levels of NORM of significance, whereas production brine is known to contain elevated NORM levels. Radium-226 is the primary radionuclide of concern from the Marcellus.

Elevated levels of NORM in production brine (measured in picocuries/liter or pCi/L) may result in the buildup of pipe scale containing elevated levels of radium (measured in pCi/g). The amount and concentration of radium in the pipe scale would depend on many conditions, including pressures and temperatures of operation, amount of available radium in the formation, chemical properties, etc. Because the concentration of radium in the pipe scale cannot be measured without removing or disconnecting the pipe, a surrogate method is employed, conducting a radiation survey of the pipe exterior. A high concentration of radium in the scale would result in an elevated radiation exposure level at the pipe's exterior surface (measured in mR/hr) and can be detected with a commonly used survey instrument...

the build-up of NORM in pipes and equipment (pipe scale and sludge) has the potential to expose workers handling (cleaning or maintenance) the pipe to increased radiation levels. Also wastes from the treatment of production brines may contain concentrated NORM and therefore may require controls to limit radiation exposure to workers handling this material as well as to ensure that this material is disposed of in accordance with 6 NYCRR § 380.4....

the disposal of NORM-contaminated [exploration and production] E&P wastes is a major component of the oil and gas NORM issue.

That sounds mostly good, though it reminds me of another issue they don't address. Steel pipes can change, generally becoming more brittle, when exposed to radiation. Maybe it's just one more corrosive effect among many, but I wish the SGEIS addressed it.

Chapter 7 on mitigation addresses some of these issues. requires tracking wastes - "record-keeping requirements and level of detail would be similar to what is presently required for medical waste". talks about spreading brine liquids on roads, as is already happening at a farm in Dryden and on state highways. However:

the data available to date associated with NORM concentrations in Marcellus Shale production brine is insufficient to allow road spreading under a BUD. As more data becomes available, it is anticipated that petitions for such use will be evaluated by the Department.

So that's an open question, for now - one I'm guessing will largely be dependent on geiger counter results.

There's also a section, 7.7, devoted specifically to "Mitigating NORM impacts". Some of it seems to repeat material from earlier in the document or report on how existing practices might work with NORM:

The discharge of licensed radioactive material and processed and concentrated NORM (such as waste filters, sludges, or backwash from the treatment of flowback water or production brine) into the environment is regulated by the Department. NORM contained in flowback water or production brine may be subject to applicable SPDES permit conditions.

Figuring out how to respond to NORM will require testing along the way:

Existing data from drilling in the Marcellus Formation in other States, and from within New York for wells that were not hydraulically fractured, shows significant variability in NORM content. This variability appears to occur both between wells in different portions of the formation and at a given well over time. This makes it important that samples from wells in different locations within New York State are used to assess the extent of this variability. During the initial Marcellus development efforts, sampling and analysis would be undertaken in order to assess this variability. These data would be used to determine whether additional mitigation is necessary to adequately protect workers, the general public, and environment of the State of New York....

The Department proposes to require, via permit condition and/or regulation, that radiation surveys be conducted at specified time intervals for Marcellus wells developed by high-volume hydraulic fracturing completion methods on all accessible well piping, tanks, or other equipment that could contain NORM scale buildup. The surveys would be required to be conducted for as long as the facility remains in active use. Once taken out of use no increases in dose rate are to be expected. Therefore, surveys may stop until either the site again becomes active or equipment is planned to be removed from the site. If equipment is to be removed, radiation surveys would be performed to ensure appropriate disposal of the pipes and equipment.

Their closing statement, of course, is pretty much "we can handle it":

The Department finds that existing regulations, in conjunction with the proposed requirements for radiation surveys, would fully mitigate any potential significant impacts from NORM.

Is it a calming report? It really depends on how much you trust the DEC to execute it.

The last section, on methane, seems a lot worse to me, though. I'll get to that in a separate article.

Posted by simon at October 1, 2011 10:24 PM in ,
Note on photos


Anon said:

You make several good points here. I hope you're planning to submit comments to the DEC.