Norwich - The $3 million bond approved by voters in 2010 to expand the Norwich Public Utilities natural gas system is nearly spent, and with the pledge that it won't cost taxpayers or ratepayers any money, utility officials hope to ask voters to approve another $8 million to continue the project.

The Board of Public Utilities Commission approved a plan Tuesday to forward a request to the City Council to place the bond item on the Nov. 6 Election Day ballot for referendum approval.

NPU spokesman Mike Hughes told the commission that $2.6 million of the initial bond already has been spent or committed to gas line expansions along nearly a dozen streets throughout the city. Utility officials first survey neighborhoods to gauge interest from potential residential and business customers, and only move to extend the line where there are enough new customers to pay for its installation and the bond debt.

The same process would be used if the $8 million new bond request is approved by voters, Hughes said. Utilities officials already have mapped out potential areas for the upgrade, concentrating on densely populated areas, subdivisions along suburban and even rural roads and neighborhoods of side streets off main thoroughfares.

The list includes Cherry Hill Road, Scotland Road from Canterbury Turnpike to the Interstate 395 overpass, Briar Hill Road, several streets off Route 169/Harland Road and the area near the city Recreation Department office at Mohegan and Reynolds roads.

Hughes used the current expansion as an example to show that current gas ratepayers and city taxpayers would not be burdened with paying off the bond.

When a new gas ratepayer hooks into the line, the new customer would pay the same rate as currently in place, but a portion of the additional revenue that brings to the entire system covers the cost of the expansion, he said.

In the current expansion, a line expansion along Stewart Road and Ethel Court cost $60,800 and needed at least nine of 14 possible homes to connect to pay for the expansion. Hughes said 13 homes have hooked up in that area.

Overall, the $2.6 million spent required a bond debt payment of $13,153 per month, and the utility actually is bringing in $28,167 from new customers already hooked up or committed to hooking into the system, Hughes said.

c.bessette@theday.com