The city's water system is inadequate, say officials, and they want residents to approve a $4.7 million project to convert the present system to irrigation purposes and install a new culinary water system.

If residents give that approval, they can expect their water bills to increase by $10.50 per month.Residents are being mailed a fact sheet about the project and a ballot. The information is expected to reach them no later than Sept. 26, and the ballots must be returned by 5 p.m. Oct. 4.

The City Council will hold a public hearing on the matter during its regular meeting on Sept. 27. In addition, an information booth will be set up on Main Street on Oct. 1. Residents also will be able to drop their ballots off at the information booth.

City Engineer Lorin Powell said that since the mid-1970s, the city has been formulating a plan to change the system.

In 1987 the City Council commissioned Arix Engineering to examine options for upgrading and improving the system.

Chief among the reasons for overhauling the water system are population increases and distribution problems.

"Since the last major improvements were made to the system in the 1960s, the population in Lehi has doubled," Powell said. Significant commercial growth also has occurred.

The Arix study, completed in June, says city wells are barely able to maintain system flows, and because of inadequate reservoir storage some areas at times experience low flows or low pressure. The situation could be critical were a fire to occur during a peak-use period.

Also, the current system uses high-quality spring water for all purposes - culinary, fire and irrigation - rather than preserving the spring water for culinary use and utilizing lower-quality water for other purposes.

And, the system has approximately nine miles of asbestos- and lead-joint pipe, which creates a potential health hazard.

The study focused on three alternatives:

1. Upgrade the existing waterworks system.

2. Install a new culinary system and upgrade the existing distribution system to serve fire and urban and rural irrigation.

3. Upgrade the existing system to serve culinary and fire demands and install a pressurized irrigation system to serve urban and rural needs.

The council chose the second alternative, saying it most closely meets current and future city needs.

According to the Arix study, principal benefits of this alternative include preservation of Lehi's high-quality water for culinary purposes; elimination of irrigation ditches, resulting in improved community aesthetics; and reduced annual operating costs.

Lehi is applying for state grants to fund the project from the Community Impact Board, the Safe Drinking Water Committee and the Division of Water Resources.

If the project is approved and the funding is received, bids would be accepted next spring and construction begin soon after. Powell estimates the project would be completed in spring 1990.

(chart) Projected costs and benefits of proposed system

The water system under consideration in Lehi would cost $4,700,000. Water bills would be increased by $10.50.

Benefits of the system would include:

***Elimination of irrigation ditches.

***Reduced long-term operating costs.

***Preservation of spring water for culinary use.

***Elimination of asbestos and lead piping.