Drilling under the bay would result in more significant impacts

MANCHESTER, N.H. (July 2, 2018) – A study comparing potential methods to cross Little Bay with a new power transmission line has confirmed that the proposed burial of the line in the bottom sediment of the bay will have minimal impact on the environment, the least disruption on area residents and properties, the lowest cost, the shortest schedule and is the most appropriate method.

Based on a recommendation by the N.H. Department of Environmental Services, the N.H. Site Evaluation Committee required Eversource to conduct a detailed review, filed July 1 with the SEC, comparing the feasibility of the proposed “jet plow” burial method to that of “Horizontal Directional Drilling” (HDD), which would place the Seacoast Reliability Project power cable deep beneath the bay by means of a significant drilling operation. Full HDD would entail drilling under the entire bay. Shore Landing or partial HDD would require drilling on both sides of the bay into the channel and connecting the two bore hole cables via jet plowed cable.

“We understand the importance of selecting the best crossing method, one that’s least impactful to the environment and the community at a reasonable cost to customers,” said Eversource New Hampshire President Bill Quinlan. “Based on the results of this comprehensive study, we’re confident that the Site Evaluation Committee members will have a better understanding of why the jet plow method is appropriate for this project and why we recommend its use.”

The study determined that drilling and placing the project under the bay using HDD technology would result in more than two years of extensive construction activity on either side of the bay, require the acquisition of additional easement rights on more than ten properties in Durham and Newington, and more than double the cost of the project compared to the proposed jet plow burial crossing.


Jet Plow

Full HDD

Shore Landing (Partial) HDD

Total Project Cost

$84 million

$216 million

$184 million

Construction Period

3 months

28 months

10 months

Land Rights Required


10+ properties

10+ properties


The jet plow method would place the power cables under several feet of the bay sediment by means of pressurized water jets, temporarily suspending some sediment in the water column. The N.H. Department of Environmental Services in February recommended, with certain conditions, approval of the cable installation using jet plow methodology, but also recommended that the SEC require the feasibility study, including both the jet plow and HDD methods.

Electric demand in New Hampshire’s Seacoast region is growing at twice the rate of the rest of the state, and the operator of the New England power grid has determined that additional transmission capacity is needed to support the reliable delivery of electric power to the region. SRP is designed to improve the reliability of electric service in the Seacoast area of New Hampshire, specifically benefitting the region where the Project is located. The Seacoast Reliability Project includes proposed substation upgrades and a new 115-kilovolt (kV) transmission line connecting two existing substations in Madbury and Portsmouth.

The proposed line will pass through Madbury, Durham, Newington and Portsmouth along existing utility corridors, including the Little Bay crossing. The New Hampshire Site Evaluation Committee is considering the project’s construction application and has scheduled formal hearings beginning in late August.

Eversource (NYSE: ES) is New Hampshire's largest electric utility, serving more than 500,000 homes and businesses in 211 cities and towns, and also supplies water to approximately 9,300 homes and businesses in Hampton, North Hampton and Rye. Eversource is proud to be recognized as the top contributor to United Way in New Hampshire. Recognized as the top U.S. utility for its energy efficiency programs by the sustainability advocacy organization Ceres, Eversource harnesses the commitment of its more than 8,000 employees across three states to build a single, united company around the mission of safely delivering reliable energy and water with superior customer service. For more information, please visit our website ( and follow us on Twitter (@eversourceNH) and Facebook ( For more information on our water services, visit

Martin Murray

Kaitlyn Woods