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NITRIFICATION ACTION PLANNING

Illinois Community Water Supply Nitrification Action Planning (NAP) Requirements were adopted by the Illinois Pollution Control Board July 25, 2019.  Title 35, IL Adm Code Section 604.140 requires, ”Any community water supply distributing water without a free chlorine residual must create a Nitrification Action Plan (NAP).  The NAP must:

  1. contain a plan for monitoring total ammonia-N, free ammonia-N, nitrite-N, nitrate-N, monochloramine residual, dichloramine residual, and total chlorine residual;
  2. contain system specific levels of the chemicals in subsection (a) when action must be taken;
  3. contain specific corrective actions to be taken if the levels in subsection (b) are exceeded; and
  4. be maintained on site and made available to the Agency, upon request.”

To aid water suppliers in complying with this requirement, the IRWA has been providing training sessions throughout the state. This document reflects the presentation of the material within these programs:

The IRWA has also developed the following template (in both excel and as a .pdf document) to aid water supplies that chloraminate:  
http://www.ilrwa.org/Downloads/200504_Nap%20Plan_Draft.xlsx
http://www.ilrwa.org/Downloads/200504_Nap%20Plan_Draft.pdf

Additionally, the IRWA has recognized that water systems in Illinois have a need to better understand the disinfection practices they are utilizing.  The following FAQs are intended to be of assistance in this effort:
Groundwater Systems with ammonia
Surface and Satellite Water Systems that Chloraminate
Chlorine Requirement Worksheet (Draft not yet peer-reviewed)

To assist water supply officials, Capt. Michael D. Curry, P.E. (founder of Curry & Associates Engineers, Inc, Nashville, IL) has developed a reference document that will allow water systems to optimize the formation of monochloramine by using precise Chlorine to Ammonia-N ratio calculations.  If used, the calculations will help operational staff form predominantly monochloramine residual and minimize presence of undesirable free ammonia (or ammonium) in water leaving the treatment plant (USING THE CORRECT ARITHMETIC TO FORM MONOCHLORAMINE). Further, the U.S. EPA Office of Research and Development has developed “two web-based applications (WBAs) relevant to drinking water practice are presented to (1) simulate inorganic chloramine formation and stability, including a basic inorganic chloramine demand reaction for organic matter and (2) generate chlorine breakpoint curves. The model underlying both WBAs incorporates a well-established inorganic chloramine formation and decay model. The WBAs were developed to be freely accessible over the Internet as web pages, providing drinking water practitioners (i.e., operators, regulators, engineers, professors, and students) two learning tools to explore inorganic chloramine chemistry in an interactive manner without requiring proprietary software or user modeling expertise. The WBAs allow the user to specify two side-by-side simulations, providing a direct comparison of impacts associated with changing simulation conditions (i.e., free chlorine, free ammonia, and total organic carbon concentrations; pH; total alkalinity; and temperature). Once completed, the user may download simulation data to use offline. The WBAs’ implementation along with example simulations are described.”

The IRWA will continue to update this webpage as additional information becomes available to the association.


Illinois Rural Water Association
3305 Kennedy Road; PO Box 49
Taylorville, IL 62568
Phone: 217-287-2115

Fax: 217-824-8638
Email: ilrwa@ilrwa.org

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