You have only until Monday to comment on Sunoco’s half-baked plan for Riddlewood and Tunbridge

Sunoco has submitted a new plan to the DEP (PA Department of Environmental Protection) for the stretch of the Dragonpipe (Mariner East 2 and 2x) between the Riddlewood subdivision and the Tunbridge Apartments on Glen Riddle Road, in Middletown Township, Delaware County. The DEP is soliciting public comments, and yours are needed before Monday’s deadline.

In this blog post, I outline some of the issues that I find worrisome in the plan. I encourage you to read the plan yourself. It is available on the DEP website here.

There are several obvious problems with Sunoco’s plan.

Sloppiness and errors. First of all, it is very sloppy, with errors and omissions throughout. For example, on page 11 of the section entitled “HDD Hydrogeologic Reevaluation Report” (page 24 of the PDF), it is stated that “the reports for the three geophysical survey events are provided in Attachment C”. But only one of the three is there. The DEP cannot evaluate (and should not accept) an incomplete submission. And what are we supposed to think of the mention of a “24-inch line” two pages later. Is that just a typo? On page 4 of the PDF, the report mentions that “the crossing of Glen Riddle Road and Southeastern Pennsylvania RR is in Upper Chichester Township”…. In fact, it is miles away from the nearest point in Upper Chichester Township.

It is hard to put any faith in a report containing such obvious errors.

Casing issues. The report proposes the use of “direct bore” (also known as “microtunneling”) to place a 48-inch pipe which will then serve as a casing for the combination of both the 20-inch and the 16-inch pipe. But there is not enough room inside a 48-inch pipe to hold them both safely. There would be, at most, 4 inches between the two pipes and between each of them and the casing. PHMSA (the federal Pipeline Hazardous Material Safety Administration) requires at least 12 inches between the pipes and between them and the casing. The proposed spacing is illegal.

This use of a casing presents an additional safety hazard: if there were to be a leak anywhere along the encased pipeline, the gases would almost certainly follow the casing to the one end or the other of the cased-in section, resulting in far higher risk in that area than would otherwise be the case.

There is another major problem associated with the casing: it can interfere with the use of cathodic protection, the standard technique that pipeline companies (including Sunoco) use to prevent corrosion. Cathodic protection depends on a flow of electrical current through the soil to the entire surface of the pipe. The casing is likely to prevent that current from reaching much of the pipe. Still, water will surely get inside the casing, creating the potential for rust. How will Sunoco prevent rust from forming and ultimately causing leaks, if cathodic protection can’t be used? There is no answer in the report.

Inadvertent returns. In its conclusion, the report claims that “this method [direct bore] also eliminates the risk of IRs”. IRs (inadvertent returns, or “frac-outs”) plagued Sunoco’s previous attempt to install pipe via horizontal directional drilling (HDD) at this location. But they are not “eliminated” by the direct bore technique. In fact, they are common. There was a recent article in the trade journal Trenchless Technology entitled “The Planning and Construction of Microtunneling Projects”. In its discussion of drilling depth, the article states, “where there is shallow cover it becomes much more likely for the slurry pressure to overcome the overburden pressure resulting in hydraulic fracturing of the ground”. It talks about the problems when this type of construction is attempted with the pipe less than ten feet below the surface. But that is the approximate depth of much of the route where direct bore is being proposed.

Groundwater issues. The report claims that with direct bore, “there is less probability of a groundwater discharge than with convention HDD drilling.” Sunoco had massive problems in controlling groundwater discharge in its previous HDD attempt, resulting in pollution to streams and wetlands and perhaps undetected damage to aquifers. Direct bore may have “less probability” of groundwater problems, but they are still likely, given their scale in the previous attempt. How will they be dealt with? The report says only “the contractor should plan to manage a groundwater discharge, if it occurs.” We need a better answer than that.

No real consideration of alternatives. The report dismisses the idea that there could be an alternative route for this pipeline, saying “[Sunoco] evaluated other routes around the area but reasonable alternatives are not existent due to the density of roads and developments….” In fact, however, Sunoco actually has an operating pipeline (Mariner East 1) running in a separate, parallel easement a short distance away. Was that route ever considered? Apparently it was not, which may mean that no real effort was made to explore alternatives.

There is also no discussion of alternatives to open trenching for crossing the wetlands and streams at the southern end of this stretch of pipeline. Why not? Why did Sunoco choose direct bore at some locations but not others? This needs an explanation, but none is given.

Please submit your comments. These are some of the main issues with Sunoco’s plan. Feel free to make use of them in the comments you submit. But it is more effective if you use your own wording rather than simply copying mine. The DEP needs to hear from you!

Email your comments to: Ra-eppipelines@pa.gov

Mention the DEP’s ID number for this section of the pipeline, which is S3-0620. The deadline is this Monday, June 3.

While you’re at it, why not copy your local state representative and senator? They need to hear your opinion too.

—

I’m grateful to my friends at Clean Air Council in helping me to identify the issues with this report.