Authors:

Bernard B. Sheff, P.E.
STS Consultants, Ltd.
3340 Ranger Road
Lansing, MI 48906

Robert V. Rogers & David J. Murrell
Prolime Corp.
58610 VanDyke Avenue
Washington, MI 48094

Abstract

A method of land reclamation has been developed and patented utilizing residual lime from water treatment processes. Until recently, residual lime from the water treatment was permanently stores in ponds or in certain locales and utilized as a soil conditioner in the agricultural community. The process which was developed, The Prolime Process (Patent No.5199822), utilizes the beneficial properties of the lime sludge and soil in preparation of a chemically inert fill for reclamation of land to meet different end use requirements. The process has been successfully utilized at five locations in south central Michigan, and has proven to be a responsible and effective reuse of the lime materials, providing a suitable foundation for a variety of future land uses. This paper will provide specific information regarding the patented process, in addition to reviews of the sites that have been reclaimed

The process commences with initial testing of the residual lime material for various metals and trihalomethanes. The testing is performed on a total basis in an attempt to determine if the metals of interest lie above state or federal regulatory requirements. If a situation presents itself where a metal of interest is found above acceptable concentrations, leaching tests specifically on the lime or more sophisticated testing of the native soil/lime mix may be performed.

Once it is known that the material will pass chemical testing, samples of the native soil in which the reclamation is to take place are collected, and various geotechnical tests are performed. This geotechnical testing involves combining various proportions of residual lime and soil and completing a series of tests to determine strength, compressibility and permeability. This testing provides the opportunity to optimize the mixture for the desired end use for the reclamation area. That is, for end use consistent with light construction, a lime/soil mixture providing higher bearing capacities would be used in the field. Conversely, in an area with an end use associated with a park or baseball diamonds, a lower bearing capacity can be designed for.

Specific projects where this has been utilized include reclamation of five sand/gravel pits, in addition to in-place pond closure. The on-site pond closures included the removal and stockpiling or staging of lime from a dewatered pond. The stockpilied lime was mixed with a suitable native soil and replaced in the excavation, providing a bearing capacity of 2,000 lbs. per square foot (psf), suitable to reclaim the existing lime pond facility to a city park. Four gravel pits were reclaimed for various recreational uses, with one pit scheduled for light residual construction.

For a copy of the full article, call STS Consultants at (847) 279-2477.