White Paper

White Paper


An Analysis for Central Iowa Public Water Suppliers and Their Customers


When evaluating the factors affecting the need for the expansion of facilities at Des Moines Water Works (DMWW), the primary factor is increased demand for water in the metropolitan area due to population growth.i

Another factor that impacts infrastructure is the quality of the surface water. Recent analysis indicates that levels of nitrates in the Raccoon and Des Moines Rivers have shown no statistically significant trend in almost 15 years.

Some DMWW utility investment models and water treatment processes have not yet been thoroughly explored. Ensuring that appropriate investments are made to keep up with a growing population, while taking into account reasonable projections for both future growth and source water quality, is crucial.

Currently, the DMWW facility serves Des Moines and more than 20 surrounding communities and water districts. Significant capital costs are being driven by this growth, but the suburban communities that make up more than half of total water consumption do not have a voice in recent decisions that have directly impacted ratepayers.

This analysis will address the following three issues that need to be considered before additional funding is committed to capital improvements by DMWW:

  1. What is causing the need for infrastructure upgrades?
  2. What does long-term data say about nitrate trends?
  3. What treatment processes should be considered?

“The primary factor affecting the need for expansion of DMWW facilities is increased demand for water in the Des Moines metropolitan area due to population growth.”
— Former DMWW CEO L.D. McMullen

It stands to reason that if more water is being used, more water will need to be treated. Infrastructure improvements will need to address capacity issues first and foremost, and should be scalable, in order for the utility to treat more water, as it is needed.

“If the existing three treatment plants were available and the water demand was as it was in 1990, there would be no need for additional nitrate treatment.”
— Former DMWW CEO L.D. McMullen


i McMullen (2016), review of CH2M March 2016 Nitrate Management Plan

ii Des Moines Area Metropolitan Planning Organization (2015), Forecasting Our Growth

iii Schilling K, January 2015. Nitrate and Phosphorus Concentration Trends in Iowa’s Rivers. Presentation to the Water Resources Coordinating Council, Measures Subcommittee, Des Moines, IA

iv C.S. Jones, A. Seeman, P.M. Kyveryga, K.E. Schilling, A. Kiel, K.S. Chain, and C.F. Wolter (2015), Crop Rotation and Raccoon River nitrate; Lynn Betts, Corn and Soybean Digest (2016), Cropping system changes may mean reduced nitrates

v U.S. Environmental Protection Agency, Aquifer Recharge and Aquifer Storage and Recovery

vi R. David G. Pyne (2003), Water Quality in Aquifer Storage Recovery (ASR) Wells

vii Black & Veatch Project No. 184920, Feasibility Study for the Development of a Regional Water Production Utility (prepared for Central Iowa Regional Drinking Water Commission)

ix C.T. Green. B.A. Bekins, S.J. Kalkhoff, R.M. Hirsch, L. Liao, and K.K. Barnes (2014), Decadal surface water quality trends under variable climate, land use, and hydrogeochmical setting in Iowa, USA