To Filter or Not To Filter

(from Maine Townsman, September 1990)
By Jo Josephson, Assistant Editor

Four publicly owned water systems serving four municipalities—one small, like Bethel, two medium-sized like Farmington and Wilton, one large, like Lewiston—all currently rely on surface water for their source, be it ponds, lakes or streams.

Each is complying with the requirements of Surface Water Filtration Rule of 1989 in its own way.

Bethel and Lewiston are each seeking exemptions to the filtration requirement, relying instead on their ability to control and/or protect the surrounding watershed.

Wilton and Farmington currently draw their waters from the same pond. Wilton is planning to filter the water; Farmington is planning on abandoning the pond and drilling a well into a large underground lake.

A closer look at their situations and what led them in the direction they are going follows:

Bethel

The Bethel Water District  was organized in 1968 after it was purchased from the private Bethel Water Company, that in turn was formed in 1890. The three trustees of the district are appointed by the board of selectmen.

The District serves 500 customers in West Bethel Village and the Central Village of Bethel through 20 miles of line: 450 receive their water from Chapman Brook which runs on the south side of the ridge that the Sunday River ski area is on; the other 50 receive their water from a deep well.

The source, described by licensed operator, veteran trustee, and president of the district Bob Sanders is a "very nice mountain stream" located four miles from the village. It draws its water from a watershed encompassing 2,300 acres, "give or take."

According to Sanders the "vast bulk of the watershed," which is located in the adjacent town of Newry, is owned by the Bethel Water District; the rest is owned by Sunday River.

So it makes sense that the district would opt for the exemption route via assured control of the watershed.

The current system of treatment is to chlorinate and fluoridate the water and to shut off the supply when a major rain storm is impending to avoid the associated turbidity that would require filtration.

The average user bill is between $25 and $30 a quarter or $100 to $120 a year, with decreasing rates beyond the basic rate for large users. Billings are metered.

Sanders figures it would cost the district one-half to three-quarters of a million dollars to build a filtration plant and that does not include the "small" problem, which is the cost of running it. With two almost full-time men running it, the operating costs currently come to $100,000 a year.

At seven percent interest on a three-quarter million dollar loan and a $25,000 salary for an additional employee to run the filtration plant, Sanders figures the current rate would double.

"There is no sense in spending money to make a worse product," says Sanders, who explains that filtering would destroy the good taste of Bethel's water. "And besides, we are down to the level most filter plants would like to put out," he argues, noting that the Public Utility Commission has put Bethel's water in the top ten percent in the state.

However, he points out there is no free lunch, that the demands on those who opt not to filter are just as great or even greater than those who do.

"Watershed protection is a catch-all word," says Sanders. "Some of the requirements are spelled out clearly, others are not. There are quite specific limits on turbidy and coliform count; on the other hand, it is harder to judge what might happen in the watershed and how to keep control over what might happen."

To show that they can come into compliance by not altering the water, Bethel has upgraded its chlorinator system and installed a new valve to shut off the flow when increased turbidity occurs. It plans to purchase additional monitoring equipment.

"We are developing a more precise and more reliable version of our current system," explains Sanders, who says he expects to spend less than $50,000 when the project is completed. Going the non-filtration route, Sanders says he expects the rate increase to be only 25 percent. The filtration route would have raised the rates 125 percent.

As far as the hydrant rate goes, under the current plan he sees it increasing by about $10,000 a year from $25,000 to $36,000 a year.

Money for compliance will "come slowly" out of the operating monies.

Lewiston

With 9,000 customers and 150 miles of line, the Water Division of the Lewiston Public Works Department is one of the larger water systems in the state. It pumps over six million gallons of water a day through its lines.

Its source of water—Lake Auburn— covers over 2,000 acres; its watershed encompasses over 15 square miles and includes Auburn, Turner, Minot, parts of Hebron and Buckfield. The City of Auburn, which shares the supply, owns about 60 percent of the shorefront and 600 acres of land in the watershed. None of the watershed is located in Lewiston.

Currently Lewiston chlorinates and fluoridates its water and adds sodium silicate to raise the pH of the water and stop corrosion of the pipes.

According to Lewiston City Engineer Christopher Branch, when the city became aware of the 1986 Amendments to the Safe Drinking Water Act, it contacted Auburn to go in on a joint study to see if they could join forces and acquire an exemption to the rule.

The study has cost them $400,000. To date, the engineers say it should be possible for them to get an exemption to the filtration rule:

—If they relocate their intakes farther off shore and deeper down...

—If they go ahead with a very stringent watershed protection program, including the development of a watershed authority...

—If they change their disinfection program from one of chlorination to ozonation to eliminate the carcinogenic trihalomethanes (THM's) produced when chlorine reacts with organic materials in surface waters.

Branch estimates that to go the filtration route, including ozonation, would cost Lewiston about $16 million.

The cost of exemption would come to about $10 million and would include land acquisition, relocation of the intake pipe, and construction of a shared ozonation facility.

Branch figures the latter route will raise the current rate by 100 percent with monies coming from the sale of city bonds. The city has an AA rating.

Like the City of Augusta, the rates will be raised gradually over a period of several years, as various phases of the project are undertaken and bonds are issued.

While Branch feels the filtration rules come down hard on Maine, he admits that some of the improvements Lewiston is undertaking were ones that needed to be done, like the installation of a joint intake pipe with Auburn.

Branch says that meeting the 1993 deadline will be close.

Wilton

The publicly owned Wilton Water Co., with 23 miles of water mains and two water storage reservoirs currently serves approximately 950 customers, including several large industrial users such as Bass Shoe Inc. and Forster Manufacturing Inc., and the 200 customer village of North Jay.

In all, the company supplies its customers with 750,000 gallons a day drawn from the 338 acre Varnum Pond, which it shares with neighboring Farmington.

According to Sewer and Water Superintendent Louis Beachamp, Wilton has opted to go the route of filtration, because at a cost of $2.1 million it was the cheapest of several alternatives explored in a $25,000 engineering study.

Because the town owned so little of the 2,560 acre (four square miles) watershed which is located in three towns surrounding the pond and because it would have had to acquire about 11,000 linear feet of shorefrontage to protect the pond at a cost of more than $2 million, the total cost of seeking a waiver would have come to $3.7 million.

It would have cost $2.7 million to go for groundwater; $2.8 million to go for slow sand filtration, and $2.3 million to buy water wholesale from its neighbor Farmington, which has opted to go underground, rather than filter surface water (see below).

Wilton plans to purchase a predesigned filtration system—a packaged treatment plant—as it is less costly than a conventional plant.

Major funding is being sought from FmHA, approximately $1.7 million in a low interest (5 percent) loan and a $1.9 million grant.

Beauchamp figures that when all is said and done, the current average rate of $32 a quarter or $128 a year will double to $256 a year for residential users.

"What's good water worth," he asks, noting that as he sees it, at the current rate residents are paying one-tenth of one cent per gallon.

Currently the department's operating costs are $260,000 a year, with $75,000 coming from fire protection or hydrant rental. Beauchamp sees the operating costs rising $100,000 a year, from $260,000 to $360,000 and the hydrant costs rising to $110,000.

Beauchamp does not worry that filtering the water will reduce the quality of its taste; it depends on the source and how the plant is operated, he says, noting that in 1989 Wilton water was recognized as being the best tasting in the state by the Maine Rural Water Association and the Maine Division of Health Engineering.

Farmington

With 100 miles of water main, the Farmington Village Corporation serves 1,500 customers with two-thirds of its waters drawn from Varnum Pond and one-third from a drilled gravel-packed well located in the intervale of the Sandy River. At 700,000 gallons a day it provides its users with 290 million gallons a year.

However, unlike Wilton, which also draws its waters from Varnum Pond, Farmington will not be building a filtration plant to comply with the requirements of the Safe Drinking Water Act. Instead, it plans to develop a new gravel well along the Sandy River.

According to Thomas Holt, superintendent of the water department, if it went the route of filtering the pond water, the department would have had to upgrade five miles of its line to meet the current and expected growth of the community. The new lines and the new plant could have cost an estimated $3 million.

But, because Farmington is lucky to be located over an excellent aquifer that stretches from New Sharon to Strong, the costs associated with drilling a well are much less, like, half, says Holt. Not only will it cover the cost of a filtration plant, but also a new pumping station and at least two miles of new line.

Farmington started the process early. Armed with the results of an engineering study completed in March 1989, it has already applied for and received monies from Farmers Home Administration, a $1 million loan and a $489,000 grant.

While the loan could have brought about an eight to ten percent increase in the current residential rate which at its minimum is about $25 a quarter, it won't.

Instead, all of the additional revenue needs, about $40,000 a year, will be taken up by an increase in the hydrant rate, which, at 19 percent, Holt points out was well below the maximum 30 percent allowed by the Public Utilities Commission.

As a result, Farmington's hydrant rental is slated to rise from approximately $80,000 a year to $120,000 a year.

In doing so, local users were spared a direct rate increase over their current minimum rate of $25.26 per quarter.

Holt looks favorably on the Safe Drinking Water Act, saying it gave him the boost to put in new lines and increase the system's capacity.