More Questions About Large Propane Tank, Some Answers
Searsport Votes on Tank March 10
Thursday, March 01, 2012 10:04 AM
DCP Midstream, a Colorado-based company that is one of the largest propane brokers in the U.S., is planning to build one of the largest propane storage tanks in the county at the industrial zone at Mack Point in Searsport.
The Liquified Petroleum Gas Terminal Moratorium will be voted on at the annual Searsport Town Meeting on Saturday, March 10, at the Searsport High School, 24 Mortland Road, Searsport. The town meeting begins at 9 a.m.
The warrant article begins . . .
ARTICLE 40. To see if the Town will vote to approve a Liquefied Petroleum Gas Terminal Moratorium . . .
The moratorium, if passed, would not allow permit approval for an LPG terminal or storage for 180 days (retroactive to November 23, 2011) and would establish a review committee to assess existing land use ordinances to determine if they protect the "health, safety and welfare of the citizens of Searsport." Any proposed ordinance changes would go before voters. Selectmen would have the power to extend the moratorium for up to an additional year.
It is not going smoothly.
On Saturday, March 10, residents will get the chance to vote on a moratorium that would temporarily halt the town permit for the DCP Midstream development and would allow a citizen committee to review existing municipal codes to see if the "public health, safety, and welfare" is protected. That could take a long time. Searsport is not historically known for consensus when it comes to land use issues.
In Searsport, DCP Midstream has hired 10 part-time canvassers to go door-to-door to talk to residents about why it is important to defeat the moratorium, according to DCP spokesperson Rosslyn Elliot.
Several surrounding municipalities, including neighboring Belfast and Stockton Springs, have recently weighed in by officially expressing concern to the Army Corps of Engineers that the regional economic and environmental impacts of the proposed development be more thoroughly assessed before Army Corps approval is granted.
The Army Corps permit to DCP Midstream is pending.
Meanwhile, the economic impact study just completed by University of Maine economist Charlie Colgan may shed light on what impact the development would have on tourism, property values, town infrastructure and town revenue. The report will be made public this week.
Concerns about the propane tank range from visual effects to whether it will blow up like an atom bomb to how local road conditions would be affected by increased truck traffic.
The visual impact is real. Unlike the rest of the waterfront industrial zone, the tank will be visible from Route 1 and, due to its height (138 feet), will be more visible to the surrounding area than the existing tanks at Mack Point. Questions about the sound impact and how visible the lights and flare for the tank will be are also being raised.
For its part, DCP Midstream chose the site because of access to the marine port, railroad and truck routes. According to Elliot, they expected little opposition to a development in an existing industrial zone where fuel storage is well established. The DCP plan for the 23-acre site includes the 22.7-million-gallon insulated propane storage tank, an additional 90,000- gallon propane tank for on-site use and two 1,000-gallon tanks to store the stinky chemical methyl mercaptan, which is added to propane so a leak can be detected by smell. The site will also have a 640-gallon diesel tank to power an emergency generator, an emergency fire-water pump with a 280-gallon diesel tank, and two large buildings that will stand 20 feet high.
It will be a short distance from the Irving fuel tank farm, the General Alum Chemical plant and Sprague Energy. DCP plans to offload propane to the storage tank via a pipeline from tankers that berth at the Sprague marine terminal.
Some are concerned that the propane tanks could blow up, as tanks have been known to do.
The National Fire Protection Association (NFPA), an international organization that develops scientifically based safety standards, has a set of U.S. LPG codes (NFPA 58) that legally guide propane storage and delivery. (LPG, often referred to interchangeably with propane, is predominantly propane but includes ethane and butane.)
The LPG codes were updated for 2011.
Denise Beach, the NFPA senior engineer for the LPG codes, explained the NFPA role.
"We do the technical end," said Beach. "We don't have anything to do with enforcement. That would be state-
level enforcement and there might also be additional local fire codes."
Beach noted that the local fire department would usually be involved in oversight.
She also demystified the process of how a propane tank can blow up and under what circumstances that can occur.
Propane is a liquid inside a storage tank, whether that is a hot-dog-shaped silver cylinder behind a restaurant or a bulk dome-shaped tank, like the one proposed at Mack Point.
Liquid propane is not flammable, nor is it explosive. It must be vaporized into a gas with the right combination of propane and oxygen to ignite.
Beach explained that a boiling liquid expanded vapor explosion (BLEVE) can occur when the welded seams of a propane tank fail. This happens either when a fire is already ignited in the area (either because there was a gas leak or from some other cause) and is impinging on the tank, or if the tank is corroding and the metal fails, allowing a liquid gas leak that mixes with enough air to form an ignitable gas.
She used the typical silver cylinder tank behind a burning restaurant as an example.
"Pressure builds up inside the tank as a result of the heat on the outside, and the pressure relief valve, which all propane tanks have, can't handle the increased pressure fast enough," said Beach.
The welded seam fails and the now highly pressurized propane has enough oxygen to ignite in an explosive blast that can send shrapnel out into the area.
"It is not a bomb," said Beach, meaning that the tank cannot explode without provocation or be tripped like an explosive device. "It is a violent rupture in the tank that creates a flammable environment where the fire ignites the vapor cloud," said Beach.
Excess heat is key to creating a BLEVE, she said, and it is not unique to propane. A BLEVE can happen with other fuels and is more of a concern on older fuel storage tanks, since tank safety codes are updated regularly based on the latest research and technology. Newer tanks are likely to be the safest available, which does raise the question: how old and how safe are the other storage tanks at Mack Point?
Beach explained the difference between the silver cylinder tank and the one DCP Midstream is proposing.
"It is not the same type tank at all," said Beach, who was not personally aware of the Searsport proposal, but was familiar with the type of tank proposed. The DCP tank would be insulated, double-walled and refrigerated. The large size of the tank makes it safer because the volume of liquid inside would be extraordinarily difficult to heat to boiling, according to Beach.
"First, a fire would have to already be going on in the area for a long time with no steps to put it out, and second, there would have to be no one present or no water available to cool the tank," said Beach.
According to the Maine Department of Environmental Protection (DEP) permit for DCP Midstream, which was approved last year, an emergency flare will be used to relieve internal tank pressure "during any situation resulting in the loss of refrigeration for the LPG storage tank," which could occur as a result of an extended power outage.
The flare is, in essence, a backup pressure-relief valve.
The propane industry has a good safety record overall and it continues to grow stronger as more safety measures are put in place, according to Beach.
As to the existing tanks at Mack Point, she couldn't say. The proximity of the propane tank to the other hazardous materials at Mack Point is regulated under NFPA 58.
Beach said other NFPA codes aim to be consistent with NFPA 58 regarding setback distances and safety requirements, but she couldn't speak about other codes with any authority.
"NFPA 58 is my area of expertise," she said, recommending that the full picture on the other materials stored at Mack Point would be available from experts working with the appropriate NFPA codes.Who Oversees the Development and Operation?
Beach pointed to the heart of the safety matter. There appears to be no single entity who has oversight for the big picture of the waterfront industrial zone.
Everyone has a piece.
The Maine Fuel Board is the agency that issues the gas storage tank permit to construct the facility. Permit approval requires a Fire Safety Analysis and a site inspection before and after construction, and prior to the tank going into service, to be sure that it meets the requirements of NFPA 58, according to Peter Holmes, a senior inspector at the Maine Fuel Board.
The Fire Safety Analysis includes an analysis of existing hazards in the area as well as potential hazards to off-site properties and persons affected by the proposed development; assessment of the distance between hazards and whether they meet standards; and the evaluation of the capabilities of local emergency response.
It follows an accepted format, according to Holmes, and would likely be conducted by an engineering firm or other contractor hired by DCP Midstream.
"There are no annual inspections required by the Fuel Board, but there are requirements for continuing inspections of parts of the system required by NFPA 58," said Holmes. The inspections are the responsibility of DCP Midstream.
Holmes said Maine DOT would not be involved in LPG tank monitoring, but would be involved in inspecting LPG truck and transportation safety.
Other agencies have jurisdiction over other pieces of the puzzle.
Searsport Emergency Management Director Bud Rivers said the following regulatory enforcement activities apply to the industrial zone at Mack Point and Kidder Point:
The U.S. Coast Guard does annual compliance inspections for marine facilities; the Maine DEP conducts annual inspections and responds to spills (both actual and suspected) and takes enforcement action when necessary; the Federal Railroad Administration enforces rail safety requirements; and the Occupational Safety and Health Administration (OSHA), which enforces worker safety, may perform inspections when a report occurs or someone registers a complaint or raises a question about safety conditions.
Employees who operate the DCP Midstream facility must be licensed by the state as Propane and Natural Gas Technicians and Plant Operators.
It is a long list of who is responsible for what, but licensing and regulations are one thing and oversight of the whole industrial zone is another.
It leaves open a question much larger than the DCP Midstream development proposal: who, if anyone, is authorized to do periodic inspections of the propane facility or the waterfront industrial zone as a whole on behalf of public safety or public health concerns?
Mack Point and Kidder Point are home to a number of hazardous materials that are environmentally toxic, and dozens of HazMat spill incidents of varying quantities at the industrial zone have been reported to the DEP for the past 30 years. Some spills were a couple of gallons; others were over 1,000 gallons and required HazMat disposal. At least one spill at GAC was the result of corroded equipment, according to the DEP filing. Some spills came to the notice of the town, but there appears to be no requirement for the companies to inform the municipality.
Emergency Response: Ready or Not?
As is the case with complicated questions such as these, they raise a new set of questions: Would the town of Searsport have the legal authority, either through municipal law or through the site permit granted to a developer, to inspect the DCP facility or any other industrial facilities in town?
Planning Board Chairman Bruce Probert said the planning board has not put such a condition on a developer in the past nor have they considered doing so, but the planning board probably has the authority to do so.
"We wouldn't enforce it. That would be the code enforcement officer or someone else, but we could put it as a condition of site approval," said Probert, noting that it would probably bring up legal questions. He questioned who in town would have the expertise to conduct a comprehensive inspection.
Typically, that kind of inspection would be hired out to experts, either at a cost to the town or the developer.
Town Manager James Gillway said he would review town laws to see if the municipality currently had the authority to inspect industrial facilities.
Certainly, when it comes to emergencies in the industrial zone, Searsport firefighters are well aware that the zone poses unique hazards and are trained to handle them.
Upgrades in computer modeling of hazardous incidents and their predictive behavior have recently been bought by the department. Bud Rivers said the computer models will aid in responding to any events that occur in the industrial zone by coordinating information including wind speed, temperature, humidity, fuel source and fuel quantity to predict the speed, direction and ferocity of a fire.
The fire department and emergency management team also conduct drills for HazMat emergencies. A coordinated drill will be conducted later this year with the cooperation of GAC, according to Rivers.
But, it still leaves a lot of questions on the table.
Searsport has 34 on-call firefighters in a force that has not one full-time staff person. When asked if DCP would provide their own emergency response or provide additional resources to the local emergency response, Elliot said the company had a strong safety record and confidence in the ability of local emergency response teams to respond to any emergencies.
The DCP Midstream proposal has brought the entire waterfront industrial zone into focus, spawning more questions. Will there be a coordinated safety plan with all the industrial facilities at Mack Point and Kidder Point? What provisions are currently in place at Irving, Sprague and GAC to address spills, fires and fumes? Are all chemical and storage tanks up to current code? If not, how is that mitigated? What about truck parking and handling procedures and distance requirements between existing tanks?
Regardless of whether a moratorium slows down DCP's plans or not, questions about operations, oversight, and coordinated safety at the waterfront industrial zone remain.