The Vicksburg Board of Mayor and Aldermen unsealed several bids Tuesday for a variety of work and infrastructure projects around the city.

Bids were opened for the installation of new lime slakers at the water treatment plant.

Replacing the softening unit at the water treatment plant on Haining Road, was expected to cost $1.9 million.

Public Works Director Garnet Van Norman said the city has two softening units at the plant that were installed when it was built in 1968. The No. 1 unit, he said, broke down because of age.

Lime slakers are used for high volume lime users such as municipal water departments to create a lime slurry on site with quicklime. They are an important component in converting calcium oxide (CaO), or quicklime, into a calcium hydroxide (Ca(OH)2) slurry. Quicklime is an alternative to hydrated lime because it is more affordable and requires significantly less of the chemical by weight as hydrated lime, resulting in less storage space, handling, and freight.

Lime is used to soften water by removing calcium and magnesium, microorganisms and dissolved organic matter.

The bids were from Hemphill Construction Company Inc. out of Florence, Miss.; JS Haren Company out of Athens, Tenn.; Mitchell Contracting out of Covington, La. and Thweatt Construction Inc. out of Madison, Miss.

Hemphill Construction submitted the lowest bid in the amount of $248,000 and an additive alternate of $61,000. Mitchell Contracting had the next lowest bid in the amount of $292,000 and an additive alternate of $49,000. JS Haren submitted a bid of $337,000 and an additive alternate $52,500. Thweatt Construction had the highest bid in the amount of $370,200 and an additive alternate of $43,000.

A bid from Suncoast Infrastructure, Inc. out of Florence, Miss. for the continuing sewer assessment program was opened. The bid was in the amount of $700,808.67. Suncoast Infrastructure, Inc. was the only company to submit a bid.

The assessment program is required under a consent decree with the Environmental Protection Agency that requires the city to assess, evaluate and replace and upgrade its 108-year-old sewer collection system over the next 10 years. The consent decree was reached after an EPA investigation found the city had allowed untreated wastes to flow into local streams and the Mississippi River.

Van Norman said the program was estimated to cost $3.118 million based on the cost of a similar EPA-mandated project in Memphis, Tenn., which is under a similar consent decree.

“We really don’t know what we’re going to find once we start assessing the system,” Van Norman previously said. “We’re talking about a 100-year-old system. There’s no telling what’s down there.”

The board also opened two sealed bids for grass cutting at Cedar Hill Cemetery.

One was from Charles Scott with Scott Lawn Service in the amount of $10,000 per cutting at 16 cuttings a year for a total of $160,000. The other bid was from B Hynum Mowing in the amount of $7,995 per cutting at 16 cuttings for a total of $127,920.

All those bids were taken under advisement and the board is expected to make a decision at their next meeting Monday, March 16.

The board accepted a bid from JS Haren for $616,240 to rehabilitate the primary clarifier at the wastewater treatment plant on Rifle Range Road.

The 41-year-old clarifier was installed when the plant was built in 1973 and is one of two clarifiers that allow solids to settle out of the wastewater during the treatment process. The clarifier rehabilitation is not part of the EPA consent agreement, but is required under the city’s license and the Mississippi Department of Environmental Quality certification regulations.

The city applied for and received a Mississippi Development Authority community development block grant to cover a portion of the project’s cost.