Photo Courtesy of: Wikimedia Commons
The Challenge
The Columbia Water and Light Department, which serves nearly 120,000 residents in Central Missouri, uses a lime softening technique as part of its drinking water treatment. The lime residuals from this process are then transported via truck to farms for agricultural application.
As time has passed, there is less of a need for immediate local application of the treated lime residual. The city is currently trucking the material many miles and several counties away for eventual use. Shipping these large quantities long-distance is unsustainable, both financially and in terms of the environmental impacts. Growth in population and water demand will continue to exacerbate this problem.
Because of this, the city is preparing to apply for a permit to release the lime residuals into the Missouri River. They are also interested in exploring other innovative options for dealing with the lime residual.
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The City Partner
Ryan Williams is the Assistant Director of Columbia’s Water and Light Department. Columbia Water & Light was formed by voter approval in 1904. Since that time, the utility has been furnishing Columbians with low cost, reliable electricity and high quality water. Every customer is an owner of the utility and has a say in how the utility is run. Operational recommendations are made to the Council by the Water and Light Advisory Board. Final decisions concerning Columbia Water & Light are made by the City Council. The utility is run as a department of the City of Columbia.
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A Scientific Partner
Ryan Williams is seeking scientific input on the overall environmental impacts of a possible discharge of lime residual into the river. Importantly, those impacts must be weighed against the implications of maintaining the existing solution of trucking the lime residual material a great distance. As any lime discharge into the river causes discoloration of the local environment, knowledge of the possible geological and ecological impacts of such a discoloration would be helpful.
Ideally, the candidate can provide input on best practice regarding lime residual treatment and discharge. An analysis of alternative treatments or recycling methods may also be valuable.
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Timeline and Outcome
Columbia is currently finishing an anti-degradation study of the local river conditions. Carollo Engineers, Inc. of Kansas City, Missouri is being retained as the professional engineering service required to supplement the preparation of a Best Professional Judgment (BPJ) Study of the potential residuals handling alternatives at the McBaine Water Treatment Plant. The purpose of this study is to identify potential permit limits that might preclude further pursuit of a Best Professional Judgment Study in light of the antidegradation requirements recently required by the Missouri Department of Natural Resources (MDNR).
- As a scientific partner, you will review the results of this study and provide your input into a Best Professional Judgement report in early 2016. Based on your findings, this report may be part of the city’s potential application for a discharge permit from the state’s Department of Natural Resources.
- Any alternative strategies for the lime residual would need to be offered during this same timeframe, and you may be asked to compare those solutions with the option of returning the lime residual directly to the river.
Desired Skills and Expertise
- An understanding of lime treatment processes and residual applications, as well as knowledge of best practices used in the reduction, reuse, or discharge of the lime residual.
- Familiarity with the Missouri River and a working knowledge of Missouri Department of Natural Resources policies is a plus, but not required.
- Similarly, the ability to interact locally with the city is a plus, but not required
- Ability to interact well with local stakeholders and respect community input on the project
