Category Archives: AC Mitigation

AC Modeling – The Basics

AC Modeling Overview

Pipeline Right-of-Way
AC Modeling enables pipeline operators to evaluate and plan for mitigating AC corrosion.

There continues to be much greater awareness by pipeline owners and regulators of the adverse interactions (AC Interference) that can occur between buried pipelines and above ground high voltage AC transmission systems that share some parallelism in a common right of way. When AC Interference conditions exist, it is important that the potential impact is evaluated and when necessary mitigated. For many applications, the most cost-effective approach to assess and mitigate the impact of AC Interference is to use a complicated computer AC modeling program.

The term AC Modeling really covers multiple modeling evaluations as an AC corridor can often be quite complex. They may include multiple HVAC transmission systems and multiple pipelines in a common corridor or multiple shared right of ways along a long length of pipeline. Each may require its own AC modeling. In addition, the modeling looks at several different risks assessing how the pipeline is affected by steady state AC induced current, the impact of fault current along the pipeline and an evaluation of the impact of a fault current on above ground appurtenances to assure safe operation in accordance with IEEE std. 80 step and touch potential criteria.

Thus, it is very important for any successful AC modeling effort that the modeling software be of an extremely high quality and capable of properly handling the complex interactions of these various networks. The engineer or technician developing the model must also have sufficient experience and expertise to properly configure and operate the model, and evaluate the results.

AC modeling involves four key phases:

  1. Data Collection
  2. Creating the Model
  3. Establishing criteria
  4. Evaluating mitigation strategies

Data Collection

The data collection is critical to a successful modeling effort (the old adage garbage in = garbage out is quite applicable for these projects). The data requirements can be broadly broken out into three categories:

  1. The characteristics of the AC Transmission Line(s)

    • Physical geometry data on the tower including GPS location, height, # of AC circuits, tower configuration, height of each conductor, lowest point of each conductor, separation distance between conductors, shielding wire type and location, location of any phase transpositions, etc…
    • Electrical data on the Transmission Line(s), including peak and average AC Load (in each direction), fault current max and duration.
  2. The characteristics of the Pipeline(s)

    • GPS location, depth of cover, coating type, coating resistance, pipeline diameter, pipeline wall thickness, location of all above ground appurtenances, location of all CP test stations and bonds to foreign structures.
  3. The characteristics of the Environment

    • Detailed soil data at multiple depths along the length of the pipeline, location of any crossings, presence/location of any foreign CP Stations or other interference conditions.

Collecting all the appropriate data often requires some field studies and working with both the pipeline owner(s) and the transmission line operator to get the required data. In some cases, the modeler cannot get all the required information and must make an educated guess the accuracy of which can affect the quality of the results.

Creating the Model

AC Modeling
AC modeling software enables input of pipeline, transmission and environmental characteristics

Once all the data is collected, the modeler creates the model space detailing all the pipelines and HVAC systems and providing the requisite parameters associated with each of these elements. There are several commercially available AC modeling software packages that each have their own format for inputting the pipeline, transmission and environmental characteristics. Once the model has been built, it can take hours, days and in some cases weeks of processing time to run simulations and for the model to provide the results of the simulation.

Evaluating the Model Results Against Established Criteria

The results of the initial model run need to be evaluated against the criteria that is established by the pipeline owner. In the absence of specific guidance from the owner, MATCOR’s default criteria are:

  • No more than 20 A/m2 AC current density for mitigating AC corrosion during steady state induced AC current
  • 3000 volts maximum coating stress during fault conditions for newer FBE type coated pipelines in accordance with NACE standard SP0177-2014
  • 15 VAC for step and touch potentials at above ground appurtenances

For any given application, one or more of these criteria may be exceeded along the model’s area of analysis.

Adding AC Mitigation and Reevaluating the Modeling Results

Once the initial unmitigated results have been evaluated against the criteria that has been established, the modeler then adds, based on their experience with these systems, a mitigation scheme to the model with grounding at selected locations. This is often an iterative project where the model is run and the results evaluated and then if necessary additional mitigation can be added or excess mitigation can be removed and the model rerun again in search of an “optimized” modeling solution that addresses all of the threats and results in meeting the requisite criteria.

Final Report

Once the AC modeling effort has developed a solution, the modeler develops a final report. Typical components of a final report include an introduction detailing the scope of the study, graphical illustrations of the pipeline(s) and transmission line(s) overlaid on to a satellite image, description of the modeling software used, detailed graphs/charts showing the results of the modeling, detailed drawings and bill of materials for the mitigation solution being recommended and appendixes with the underlaying data.


AC Interference issues can be quite complex and modeling often offers the only valid way to assess and mitigate the risks from AC faults and steady state induced currents. When considering AC modeling it is important to look at the model being used and the modeler performing the evaluation.

Learn about our AC modeling and mitigation solutions:

Questions about AC interference, modeling or mitigation? Please contact us at the link below. Our experts are happy to help.

Contact a Corrosion Expert

Additional Related Content

SGB Scaffolding and Industrial Services Appointed MATCOR Distributor in India

Chalfont, PA (November 12, 2015) – MATCOR, Inc., the trusted full-service provider of proprietary cathodic protection products, systems, and corrosion engineering solutions recently announced that the company has appointed SGB Scaffolding and Industrial Services Private Limited (SGB India) as its distributor in India. SGB will take over the MATCOR operations in India. Both MATCOR and SGB India are Brand Energy & Infrastructure Services (BEIS) companies.

SGB India, headquartered in Hyderabad, India, provides industrial services and construction related solutions. This move to incorporate MATCOR’s proprietary cathodic protection and AC mitigation solutions enables SGB India to deliver a broader range of services and solutions to customers throughout India.

Shailesh Javia will lead operations in relation to cathodic protection products, systems, and corrosion engineering solutions out of SGB’s office in Ahmedabad, India. The office is located at 106, Sakar – V, B/h. Natraj Cinema, Opp. H.K. College, Ashram Road, Ahmedabad – 380009, Gujarat, India and staff can be reached by phone at +91 (0)79 26588551 or email at

“With the significant infrastructure development expected in India, local operators will benefit greatly from MATCOR’s turnkey corrosion prevention solutions and SGB’s industrial and construction solutions,” said Kevin Pitts, President of MATCOR.

India is home to many major companies in the oil and gas, chemical, power, water and other infrastructure industries. These companies operate assets such as pipelines, plant piping, offshore structures and storage tanks that require the corrosion prevention products and services provided by MATCOR. In addition, India has a growing network of pipelines laid in overhead electrical right-of-way corridors. Pipelines along these corridors experience AC interference as great as 50-75 VAC, which can cause corrosion and a hazardous environment for workers and the public.

SGB India will provide operators in India with full array of cathodic protection and corrosion engineering services, in addition to a full range of AC mitigation products and services to combat pipeline AC interference.


About SGB India

About Brand Energy

MATCOR to Present AC Mitigation Technical Paper at the 2015 National Association of Corrosion Engineers (NACE) Conference

MATCOR to Present AC Mitigation Technical Paper at the 2015 National Association of Corrosion Engineers (NACE) Conference

Chris Sheldon, Practice Lead - Utilities, MATCOR, Inc.
Chris Sheldon, Practice Lead – Utilities, MATCOR, Inc. to present AC Mitigation Comparison at Corrosion 2015

Chalfont, PA (March 12, 2015) – MATCOR, Inc. the trusted full-service provider of proprietary cathodic protection products, systems, and corrosion engineering solutions will present a paper comparing three AC mitigation methods to reduce corrosion in pipelines at the annual NACE conference held at the Kay Bailey Hutchinson Convention Center in Dallas, Texas March 15-19, 2015.

Modern AC Mitigation Performance Testing and Comparison Christopher Sheldon, PE March 18, 2:25-2:50 p.m. Room 141

The presentation explores AC mitigation grounding systems to prevent corrosion leaks in pipelines. Using a test bed at an electric and gas facility, the ability to reduce the AC voltage were measured via three methods: zinc ribbon anode, bare copper grounding and an engineered system. The data suggests AC mitigation installed at least ten feet or more from the pipeline is effective which also offers additional safety to the installers.

“With more and more pipelines laid in electrical right-of-way corridors, effectively mitigating AC interference has become an increasing problem for pipeline operators,” said Douglas Fastuca, President of MATCOR Inc. “We have invested heavily in AC mitigation efforts and offer a complete range of services and products to combat this important issue.”


Christopher Sheldon, PE serves as Practice Lead, Utilities and has been with MATCOR since 2011. With more than 25 years of engineering experience, Mr. Sheldon has spent the last 15 years focused on corrosion engineering. Mr. Sheldon has completed cathodic protection designs for underground gas, electric and generation facilities.  He has co-authored white papers on AC Mitigation and is certified as a NACE CP Specialist and Coating Inspector Level 1. He has authored multiple papers and speaks at corrosion conferences around the world.


Following our success in 2013, MATCOR is expanding by hiring new talent for cathodic protection, corrosion engineering jobs.

MATCOR is a full service provider of customized cathodic protection systems to the oil & MATCOR_Vertical_webgas, power, water/wastewater and other infrastructures industries.  Cathodic Protection is a technique used to control the corrosion of a metal surface by making it the cathode of an electrochemical cell.  MATCOR has an array of proprietary cathodic protection products and systems combined with high-quality corrosion engineering services, and installation and maintenance services.

In business for over 40 years, MATCOR is considered the technology leader in cathodic protection and corrosion engineering.  MATCOR is headquartered in Chalfont, PA, has a major service operation in Houston, TX, provides turnkey services throughout the United States, and has a growing list of international distributors.  MATCOR has been named to the Inc. 5,000 list of fastest growing companies in 2011, 2012 and 2013. Because of strong continued growth, MATCOR is seeking talented new team members to fill cathodic protection and corrosion engineering jobs.

MATCOR employees and culture are driven by three core principles. Whether a technician, engineer or manager, these principles guide us toward positive relationships with our clients and positive outcomes to every project we undertake.  These core values are:  We Respect Others, We Honor our Commitments and We Act in a Safe and Responsible Way.

“Our cathodic protection and corrosion engineering job openings, from technician to management positions, offer you the opportunity to grow with our team of seasoned cathodic protection experts and become part of a unique culture,” said Doug Fastuca, president of MATCOR, “As we are experiencing tremendous growth and request for our products and service offerings, this is an excellent time to join MATCOR.  In addition to competitive benefits, you can become NACE certified and enjoy other advanced educational opportunities.”

Our ideal job candidates will possess these values and hold a positive attitude.  This is a rapidly growing company with many new career opportunities.  Your cathodic protection, corrosion engineering and management job opportunity is here, today!

View the open position here:

Natural Gas Transmission Pipelines & Safety: Major Washington Expansion

The Washington State natural gas transmission pipelines and safety landscape received a big announcement this week. Multiple sections of pipeline in Washington will be expanded, according to federal filings by Northwest Williams Pipeline.

The current gas transmission pipelines are 30 inches. The proposed expansion will place 36 inch pipeline next to the old 30 inch pipeline. The construction, expected in early 2017, will also create continuity between existing 36 inch pipeline. The pipeline expansion is a perquisite for a new liquefied natural gas (LNG) export station in Astoria. The project will encompass a wide range of work, including natural gas pipeline safety and protection.

In total, the pipeline project will span 140 miles from the Oregon state and Canadian national borders. The Oregon Pipeline Company will connect the southern expansion into Oregon through an installation underground the Columbia River. The finished product is LNG that will be shipped to Asia from the Astoria natural gas terminal.

Northwest Williams Pipeline estimates the project cost at $870 million. Upon completion, the pipeline will be made available to other customers in the Northwest, including Washington and Oregon. The company also stated it expects the pipeline to generate over $10 million in property taxes, per year across Washington.

The Federal Energy Regulatory Commission (FERC) received the application request in June. FERC officials have announced the plan will be reviewed in tandem with the Oregon LNG pipeline plans.


MATCOR’s Insight That Works

The proposed pipeline expansion holds a great deal of promise for all involved. The Astoria LNG terminal is poised to service rapidly expanding markets in Asia.  Northwest Williams Pipeline will help bring a great deal of economic benefit to Washington. At the same time, the project is highly complex by joining multiple existing pipeline sections. Natural gas pipeline safety and pipe protection are large concerns. The company is making a large investment that will require expert cathodic protection to secure continued profit. Technology such as linear SPL anodes could make a huge impact for Northwest Williams Pipeline.


MATCOR is a leading provider of ISO 9001:2008-certified cathodic protection management. Our cathodic protection installation team offers turnkey project management for many corrosion engineering services, including AC Mitigation. MATCOR’s cathodic protection equipment is backed by an unmatched 10 year guarantee.

Two of MATCOR’s products nominated for Corrosion Innovation Awards

Late last week, MATCOR received notification from NACE International two of its products were selected as nominations for the inaugural MP Reader’s Choice Corrosion Innovation of the Year Awards.

The two MATCOR products nominated were “The Mitigator” and MATCOR’s “Kynex” connection.  Here is a brief summary:

Kynex Connection by MATCOR

Kynex is a unique injection molding technology used to connect a MMO/Ti wire anode to a positive anode header cable, providing a more robust connection than conventional connection technology.

The prior connection technology consisted of manually applied polyolefin heat shrinks as the outer layer—depending on the connection design employed, additional layers of sealants might be applied prior to the use of the heat shrink. These multi-step connections are all manually applied with little process control.

Kynex uses Kynar pellets injected at elevated temperatures and pressures into a mold around the anode wire and cable to provide an automated connection using the industries’ most chemically inert materials to provide a better connection.

The Mitigator
The Mitigator by MATCOR

The Mitigator is the pipeline industry’s first and only engineered gradient control wire packaged solution for AC Mitigation. Gradient control wires are the most commonly used technology for mitigating high levels of induced AC on pipelines in shared right of ways with overhead AC transmission lines.

Historically, pipeline companies would use either zinc ribbon or bare copper as a grounding wire running parallel to the pipeline. To improve the performance of the grounding wire, it is common to use a backfill material. The Mitigator provides a factory-packaged product that combines the copper wire with a special backfill packaged in an inert fabric housing ready to install.

To become this year’s recipient of the  MP Reader’s Choice Corrosion Innovation of the Year Awards we need your vote.

Follow this link, and scroll down to the online form…select Kynex as #1 and Mitigator as your #2 selection – then hit the submit button.  We would really appreciate your support.

If you are a LinkedIn, Twitter, or Facebook user and would like to be an Ambassador for MATCOR, please share this posting to your social media network.

Voting ends February 15, 2012.

Bill package targets gas pipeline safety

A state lawmaker who represents the San Bruno neighborhood devastated by a natural-gas explosion in 2010 introduced a package of bills Monday designed to prevent a repeat of the disaster, including one that would tie Pacific Gas and Electric Co.’s rates to its safety performance.

Assemblyman Jerry Hill, D-San Mateo, whose district includes the Crestmoor neighborhood where the PG&E gas explosion killed eight people, said the bills would build on recently enacted state laws mandating that pipeline operators pressure-test their gas lines, install emergency automatic shutoff valves on pipes and improve their emergency response protocols.

“Much work remains to be done … to prevent another disaster,” Hill said at a press conference outside the San Francisco offices of the California Public Utilities Commission, the agency that regulates PG&E and other pipeline operators in the state.

The package of three bills would:

— Require the PUC and pipeline operators to implement “in a timely manner” any gas-safety recommendations made by the National Transportation Safety Board.

— Require the commission to create a protection program for utility employees who disclose public safety threats.

— Order the PUC to consider the safety performance of PG&E and other utilities in setting gas rates that the companies can charge their customers.

Bill died last year

Hill introduced similar profit-limiting legislation last year, only to have it die in a Senate committee. “I vow to bring that legislation back every year until it is passed and signed by the governor,” he said.

Until recently, he said, PG&E was “gambling with the public safety – less money spent on pipeline safety inspections and pipeline replacements meant more money for profits.”

Hill said his bill tying gas rates to safety, AB1456, would “prevent this gamble from happening.” He said he was encouraged that the commission will hold a workshop Wednesday to determine how to consider safety performance in setting rates.

“The commission may be on its way to transforming itself from the lapdog it’s been to the bulldog it needs to be,” Hill said.

Hill’s legislation on adopting the National Transportation Safety Board’s gas safety recommendations, AB578, comes five months after the federal agency issued about a dozen recommendations to PG&E and the utilities commission in response to the San Bruno disaster. The board said a long history of mismanagement by PG&E of its gas system had caused the fatal explosion, and that the PUC hadn’t done enough to police the company.

Hill noted that the commission had “routinely ignored” past safety board recommendations, including that gas utilities install automatic shutoff valves on gas pipelines and replace a potentially brittle type of plastic distribution pipe, known as Aldyl-A, that was implicated in two PG&E explosions last year.

After those blasts in Cupertino and the Sacramento suburb of Roseville, PG&E announced plans to replace all 1,200 miles of its Aldyl-A pipe.

State says it’s acting

The PUC issued a statement Monday that outlined how it is complying with safety board recommendations, including requiring pressure testing of pipes, cutting pressure on gas lines whose maximum levels are in doubt, ordering records reviews and implementing a program to cite utilities promptly for safety violations.

Hill’s third bill, AB1197, would bar utilities from retaliating against workers who blow the whistle on safety problems.

PG&E spokesman David Eisenhauer said the company would be giving Hill’s measures “the attention they deserve.”

He said PG&E is already encouraging its employees to identify safety problems and said the company already prohibits retaliation against workers for raising concerns.

“Our leadership is actively requesting employees to share that information so we can investigate,” Eisenhauer said.


Northern Gateway regulatory decision expected months later than Enbridge target

CALGARY – The regulatory panel weighing the controversial Northern Gateway oil pipeline said Tuesday it will likely make its decision in about two years, several months later than estimated by the builder, Calgary-based Enbridge Inc.

The proposed 1,200-kilometre pipeline would ship oilsands crude from Alberta to Kitimat, B.C., where it would be loaded onto tankers that could transport it to Asia — providing exporters with alternatives to the United States, the biggest importer of Canadian crude.

However, as with the Keystone XL pipeline that TransCanada Ltd. (TSX:TRP) hopes to build from Alberta to refineries along the Gulf Coast in the southern United States, Enbridge’s Northern Gateway proposal faces opposition on environmental and other grounds.

Thousands of people are set to speak at hearings across northern British Columbia and Alberta between January of next year and April 2013.

The joint review panel said Tuesday, in announcing several dates for the hearings, that it expects to release an environmental assessment report in the fall of 2013, and announce its final decision around the end of that year.

Enbridge CEO Pat Daniel said in May he was anticipating an early 2013 decision, but it’s clear from the hearing schedule that won’t be the case.

The company issued a statement late Tuesday saying it “welcomes clarity around the hearing process.”

“We understand that there is significant public interest in the Northern Gateway project. The JRP seems to be ensuring that there is a thorough inclusive process, and we are supportive of that. We see value in a well-defined process and remain committed to the regulatory review,” Enbridge spokesman Paul Stanway said in an emailed statement.

Enbridge also faces a longer review process than it expected for a proposal to reverse part of an oil pipeline in Ontario.

The National Energy Board said Monday it will begin oral hearings this fall into Enbridge’s Line 9 proposal.

Enbridge originally aimed to begin work on the $20-million Line 9 reversal project in early 2012, with start-up anticipated in the fall of next year.

“While the schedule extends further into 2012 than we had anticipated, we respect the board’s desire to enable stakeholders and communities affected by the project to have the opportunity to participate in the regulatory review process,” Enbridge spokeswoman Jennifer Varey said in an earlier email Tuesday.

Opposition to major pipeline projects has grown since the disastrous offshore spill in the Gulf of Mexico after BP’s leased Deepwater Horizon rig experienced a fatal explosion in April 2010.

The pipeline industry’s reputation as a relatively reliable and environmentally safe way to transport oil was tarnished by a much smaller spill in July 2010, involving an Enbridge pipeline in southern Michigan.

There have also been periodic small-scale leaks at the original Keystone pipeline and a major spill at the Rainbow pipeline in northern Alberta operated by Plains Midstream Canada.


MATCOR hires experienced Houston based Account Manager Matthew Giardina

Doylestown, PA, November 9:  MATCOR, Inc. a full-service provider of proprietary cathodic protection products, systems, and corrosion engineering solutions announced today that  they have made another valuable addition to its sales team by bringing on board Houston based, Matthew Giardina.

MATCOR hires Matthew Giardina

Giardina joins the MATCOR team as one of the Regional Account Managers located in the Gulf Coast area.  Giardina’s responsibilities include providing account management leadership, and expanding MATCOR’s presence throughout the Gulf Coast, while focusing on the oil and gas markets.

“We are pleased that Matthew has become part of the MATCOR team.  His industry experience and desire to ensure our clients benefit from MATCOR products and services will allow him to be an asset in executing our sales strategies,” said Vice President of Sales & Marketing John Rothermel.

Giadina said, “I am excited and fortunate to work with MATCOR, and believe there is tremendous opportunity to grow MATCOR’s innovative product and services solutions.  MATCOR’s proprietary products are manufactured in-house and are unrivaled in the industry.  This gives me the opportunity to further develop the Gulf Coast market, and to help our clients achieve their corrosion prevention goals.”

Giardina brings almost seven years of experience working in the corrosion industry.  Most recently, he was responsible for growing national accounts with a leading coatings manufacturer.

MATCOR, Inc. is a leading cathodic protection and corrosion prevention engineering design firm, providing environmentally beneficial systems and services to global clients for nearly 35 years. An expert in the field of cathodic protection, MATCOR offers proprietary corrosion protection products, installation, cathodic protection testing, maintenance and complete corrosion protection project management. MATCOR specializes in protecting the infrastructure of the oil and gas, electric utility, transportation and construction industries.

Manhattan Residents expressed fears for proposed 30-inch high pressure Natural Gas Pipeline

West Side residents expressed their fears at a Tuesday Community Board 2 forum about a proposed 30-inch, high-pressure, natural gas pipeline crossing the Hudson River from New Jersey to Gansevoort St.

The Spectra Energy pipeline between Linden, N.J., and the West Village has the support of the Bloomberg administration, which has mandated that thousands of residential furnaces using high-polluting No. 4 and No. 6 heating oil be converted in the next few years to relatively clean-burning natural gas.

Jason Mansfield, chairperson of the C.B. 2 Environmental, Public Health and Safety Committee, said the forum was intended to help draft the board’s response to the FERC review before the Oct. 31 deadline for public comment.

The federal agency is holding a meeting in Greenwich Village at P.S. 41, W. 11th St. at Sixth Ave., at 7 p.m. Thurs., Oct. 20, to take public testimony.

“This is an important meeting since your comments will be entered into the record and FERC can hear from you firsthand,” Mansfield said at opening of the Tuesday forum. The Oct. 4 pipeline forum was the committee’s third in two years.

Later this week the public will be able to file comments on the project directly with FERC online through the C.B. 2 Web site at

Representatives of Spectra Energy, Con Edison and the city Department of Environmental Protection spoke at length about the need for the pipeline and the safety measures to be employed in its construction and operation.

But opponents insisted they were not convinced that a new natural gas source was really needed, much less a large, high-pressure line with potential safety risks.

Regarding safety, one member of the audience demanded, “How can we trust you?” citing the Sept. 9, 2010, explosion and fire from Pacific Gas & Electric’s natural gas line that destroyed 53 homes, damaged 120 other buildings and killed one person in San Bruno, California, near San Francisco.

Spectra said the proposed pipeline would have specially made and inspected high-strength flexible pipe with coating inside and out, buried 3 feet or more with special fill. In operation, technicians monitoring operations via robotics could remotely shut down the line.

But C.B. 2 members noted that the board last year suggested that automatic shutoff valves might be more reliable than remote control shutoff. However, Spectra representatives at the Tuesday forum said technology for remote shutoff was better than automatic shutoff technology.

“A lightning strike could trigger an automatic shutoff,” said Ed Gonzales, Spectra project manager.

The Spectra pipeline under review would cross the southwest corner of Gansevoort Peninsula, cross the West Side Highway at Gansevoort St. and terminate on the west side of the proposed Whitney Museum property.

Con Edison would build its own high-pressure, 30-inch, natural gas line from the Gansevoort terminus of the Spectra pipeline along 10th Ave. for 1,500 feet to a Con Edison connection at 15th St. at 10th Ave.

But the Con Edison connector line is not part of the FERC environmental review. Cheryl Payne, the engineer in charge of Con Edison’s gas transmission, said the connector line has not been designed yet. But she said the materials and construction method would conform to the same high standards of the Spectra pipeline.

The Con Edison connector line would also use a remote shutoff system. Like the Spectra representative, Payne said an automatic shutoff system could be triggered by an event like lightning and needlessly leave large areas of the city without service.

C.B. 2’s Mansfield said later that the environmental review of the Spectra project should include Con Edison’s connector line.

“I don’t think they really made the case that the pipeline is needed,” he added. “It just wasn’t justified in view of its potential for catastrophic damage.”

Many of the project’s opponents at the Tuesday meeting had in mind the impending rules on natural gas production by high-volume hydrofracture drilling in New York State’s Southern Tier.

Spectra representatives said the company’s business was only natural gas transportation, not production. Indeed, the draft environmental impact statement indicates that the pipeline would be able to bring natural gas from the Marcellus Shale regions of southern New York and northern Pennsylvania into the Manhattan.

Catherine Skopic, an environmental advocate, told the Oct. 4 forum that it was time for investment and exploration of renewable resources like solar voltaic cells and wind energy instead off fossil fuel.

Opponents were also skeptical about the common assumption that natural gas is the cleanest of fossil fuels, if the environmental damage of hydrofracture drilling is included in the assumption.

Speaking to the fear of terrorism, Frank Eady, a former member of Community Board 4, raised the specter of Stuxnet, a computer program that he said was used to sabotage and set back Iran’s nuclear weapons program.

“That program is out there,” he warned.

Spectra representatives acknowledged that they didn’t know about Stuxnet, but Gonzales said the company monitored potential cyberspace danger.

Mav Moorhead, a Lower Manhattan resident angrily demanded, “Who will be accountable when the neighborhood blows up?” she said, adding, “We don’t have a hospital,” referring to the closing of St. Vincent’s.