Parachute Creek spill: Day 31

This valve site is the focus of the COGCC investigation into the source of the Parachute Creek plume. (COGCC photo)

This valve site is the focus of the COGCC investigation into the source of the Parachute Creek plume. (COGCC photo)

At the Energy Advisory Board (EAB) meeting on Thursday night (4/4), after presentations from COGCC Executive Director Matt Lepore and Williams VP & General Manager Dave Keylor, the board members were allowed to ask questions. Bob Arrington brought up his explanation as to why the valve could leak in cold weather and not appear to leak in warmer weather. He told Dave Keylor he had sent his valve drawing to Donna Gray (Williams Community Affairs Rep).

B-Arrington-williams seep valveIn general, Keylor responded dismissively to Bob’s cold weather contraction theory. Though at one point he mentioned that on January 3, they had a significant event (spill) when a pressure gauge burst at the valve site where they are currently excavating (which is the focus of the current COGCC investigation into the Parachute Creek spill). Keylor said at that time Williams had determined that less than 25 gallons of fluids had leaked at the site so therefore it was not reported.

Here’s John Colson’s version (Post Independent):

Dave Keylor, vice president of Piceance Basin operations for Williams Midstream, admitted that the company on Jan. 30 had discovered a leaking gauge in the same area as a valve set that is suspected as a source of the plume leak.

But that leak, he maintained, released less than 25 gallons of hydrocarbons, far less than would be required to create the plume.

Still, he said, “Part of this investigation [into the plume leak] is, did we have more than one event? Did we have multiple events? We are continuing to investigate that.”

Bob Arrington and I remember the the date as January 3, and John Colson wrote down the date as January 30. Bob and I also remember that Keylor said “burst.” The exact date doesn’t really matter since the spill was not reported – because Williams determined less than 25 gallons spilled. The point is, sometime in January the pressure gauge burst on the same valve which is the focus of the current investigation into the source of the hydrocarbon plume. According to Keylor it was bitter cold and there was snow on the ground.

At the news of the pressure gauge event Bob Arrington exclaimed, “Ball game over!”

EAB Chair Brent Buss loudly interrupted the discussion and quickly moved on to another board member’s question.

I’ll let Bob Arrington take it from here.

**********

Bob Arrington* responds

When I proposed the cold weather situation, it was baffling to me how there could be a leak that couldn’t be found.

When I heard Dave Keylor say they “found” a burst pressure gauge, the bell went off for me. That is why I made my “game over” comment. These guys have been around for too long to write-off a burst gauge as a 25-gallon spill.

I did the calculations on a minimum 1/8″ pipe feeding a pressure gauge and the flow it can do in gallons/minute.

Flow_Calculations_4_6_13The range is 19.92 to 25.01 gallons per minute at 200 psi. The claim it only leaked 25 gallons means they would have had to be there when it burst, called in to shut off the flow or turned off the valve, and plugged it – all in 1 minute.

The more likely scenario is that they were filling a tank in the tank farm and finally noticed it was not filling as soon as it should have. In 4.5 hours they would have leaked the ~6000 gallons they claim to have later collected. When the tank didn’t fill, they then went out to find out what was happening and found the burst gauge.

The original story coming out had crews establishing the certainty of pipe locations. I believe they were really going out to deal with a spill that they thought was minor and discovered it was bigger than they thought. I think that the 25 gallon report cited was believed at first and someone finally said “we had to have spilled more than that.”

We know they were trenching in this endeavor, because they “encountered” hydrocarbons. At this juncture, I would now say they were “mapping” the plume from the get-go and did trenching when they thought they were at the perimeter. Their thinking was, the hydrocarbons would follow the disturbed earth of the pipeline to the creek first and slowly fan out to the sides.

They later discovered the truer groundwater charge from the creek, and as hydrologists studied it more they have discovered the plume went downstream on them. I feel they were addressing what they thought was a minor leak and turned out much bigger than what they went in to remediate.

I think they were also caught by surprise by an elevation groundwater flow that went around both ends of the main trench. Hence, they had high readings between the trench and stream. Still riding on their perceived “luck” of having groundwater flowing from the stream [influent] they are still hoping that none of this will get into the stream. But, considering the stream drops and bank features that exist downstream, their luck may run out.

If the flow evaluation of what the burst pressure gauge could actually do is coupled with a good estimate of how long it was burst (say the filling of a tank that took too long) they just might get the estimate of bbls [barrels] they are actually dealing with.

It may be they have only picked up one fifth of an easily possible 24-hour spill with the ~6000 gallons (142 bbl) reported. However they do need to stop the balance going in the downstream direction because it will surface at an opportune water table and stream coming to the same elevation.

**********

*Bob Arrington is a retired engineer and the Battlement Mesa citizen representative on Garfield County’s Energy Advisory Board (EAB). He also represents the Grand Valley Citizens Alliance and the Battlement Concerned Citizens.

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2 Comments on “Parachute Creek spill: Day 31”

  1. Carl Mc Williams Says:

    Based upon Bob Arrington’s assessments delineated in this particular Peggy Tibbetts blog; I herein respectfully request that District Attorney Sherry A. Caloia open an investigation into the acts and omissions of WILLIAMS MIDSTREAM and its employees, (et.al.) for possible criminal violations of COGCC statutes.

    High crimes and misdemeanors may have been committed by WILLIAMS MIDSTREAM and its employees in “covering-up” events at the Parachute Creek benzene release and a thorough criminal investigation is necessary.

  2. Bob Arrington Says:

    The formula, for those that like to calculate those things should read:
    Q=236 d2o C √ΔP/ρ = and the C has 3 different values to give the range. The “√” is the square root of the “ΔP/ρ”, “ρ” was the “= weight density” of 53, and “d2o” is diameter of orifice squared in this comment because the symbol would not duplicate in the comment format.
    Peggy had to convert an Excel copy to fit her blog and symbols often do not make the transition as d squared sub o above.

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