MERRIMACK — Several improvement projects will take place in the next few years to ensure that all of Merrimack’s public water is filtered and treated.

“... I am happy this is finally happening,” said Don Provencher, a commissioner with the Merrimack Village District. “I am definitely looking forward to when this is all on line, which at that point, 100 percent of our water will be treated.”

Starting this summer, two public wells operated by MVD that are currently offline will be filtered for perfluorooctanoic acid, or PFOA. The majority of funding to treat these two wells, known as wells four and five, will be paid for by Saint-Gobain Performance Plastics.

“That is in the final design and bidding process. We do expect work to begin on that later this year,” said Provencher, adding he hopes to have those wells back in operation in 2020.

It was three years ago when PFOA was discovered at faucets inside the Saint-Gobain plant in Merrimack, prompting a major investigation by the New Hampshire Department of Environmental Services that eventually required hundreds of homes in the area to receive bottled water, and some homes with private wells to be hooked up to municipal water.

Last month, local residents voted to have the MVD spend $14.5 million to filter four other public wells, along with other necessary improvements.

With a vote of 264-22, voters agreed to spend $3.6 million to design and construct a water treatment system for what are known as wells seven and eight. And, with a vote of 264-24, voters also agreed to spend an additional $10.9 million to treat what are known as public wells two and three.

Although all four wells have the presence of PFOA, ranging from 7 parts per trillion to about 28 ppt, the contamination levels are still below the state standard of 70 ppt; that number, however, is now being studied and could potentially be lowered.

Other significant water improvements will also be taking place in Merrimack, including a new, $4.5 million iron and manganese treatment plant that has been part of the MVD Capital Improvement Plan for several years, and a $1.3 million booster station on Turkey Hill Road that was approved by voters last year, said Ron Miner, superintendent of the MVD.

Currently, the average MVD water user pays $315 a year, which will increase by 79 percent by fiscal year 2022 with the two new bonds in place, as well as a new budget that includes a $500,000 contribution into capital reserves, ongoing debt service and more. By fiscal year 2022, the average MVD water user will be paying about $563 a year.

“The PFOA treatment is only 31 percent of the projected total increase,” stressed Miner. “The rate study assumed future budgeted expenses at a 3 percent increase per year, as well as factoring in long-term capital needs.”

According to MVD officials, the average annual water payment throughout New Hampshire is about $577, meaning MVD customers — after a projected total rate increase of 79 percent by fiscal year 2022 — will still be lower than the state average once all of the improvements are completed.