Technical: Removing Ammonia from the Drinking Water

What Are Chloramines? 

Chloramines are a mixture of chlorine and a small amount of ammonia.  While obviously toxic at high levels, neither poses health concerns to humans at the levels used for drinking water disinfection.  Click HERE for additional information regarding Chloramines. 

There are some within the community that have shown concern with the use of Chloramines for water disinfection.  From the extensive research the HBPW and it's hired consultants have done, as well as the research done by the United States Environmental Protection Agency, the HBPW agreed that the use of chloramines was the best option for disinfection.  The use of Chloramines has become one of the most common forms of water disinfection in the United States.  Chloramines, the monochloramine form in particular, has been used as a disinfectant since the 1930's. 

Because the chloramine residual is more stable and lasts longer than free chlorine, it provides better protection against backerial regrowth in systems with large storage tanks or piping systems, buildings taller than 10 stories, and dead-end water mains.  One case study done by the National Center for Infectious Diseases stated that, "Increasing use of monochloramine in water supplies throughout the United States may reduce Legionella transmission and incidence of Legionnaires' disease" (Read the full article HERE, or visit www.cdc.gov/eid). 

In 2000, the American Water Works Association published a similiar journal article that studied hospitals where outbreaks of Legionnaires' disease occured.  They found that hopsitals supplied with drinking water containing free chlorine were 10.2x more likely to have reported an outbreak of Legionnaires' disease than hospitals that used water with monochloramines.  Read the full article HERE

Additional Information

Press Release send August 28, 2015

Letter from HBPW Director of Operations

Letter to the Editor - Hannibal Courier Post sent November 16, 2015

MoDNR Response Letter sent November 23, 2015

GAC Memo presented to HBPW Board February 16, 2016


April 5, 2017

On April 4, 2017, the citizens of Hannibal voted to remove the use of ammonia as part of the city’s disinfection system by a vote of 1,259 to 894.  The proposition called for the Hannibal Code of Ordinances to be amended to include the ordinance prohibiting the use of ammonia in the public drinking water system within 90 days of approval by City Council. 

The HBPW Board has solicited a proposal from Black & Veatch Engineers to begin the process of studies, reports, and designs required to eliminate the use of ammonia in our drinking water.   The proposal is currently being written. 

April 19, 2017

The HBPW Board solicited a proposal from Black & Veatch Engineers to begin the process of studies, reports, and designs required to eliminate the use of ammonia in the drinking water.  This is the Board’s first action item required to come into compliance with the results of the Proposition 1 referendum on April 4, 2017.  During the April 18th board meeting, the HBPW Board received the first draft proposal from Black & Veatch.  The Board will review the proposal and convene next month for a special board meeting to discuss changes. 

Read the memo from Bob Stevenson to the HBPW Board HERE. 

May 9, 2017

The HBPW Board held a special meeting on Monday, May 8, 2017 to discuss and approve the Chloramine Replacement Alternative Evaluation proposal submitted by Black & Veatch Engineers.  Several changes were made to the first draft proposal given to the HBPW Board members last month, and the final document was approved. Read the approved proposal HERE

Part of B&V's scope of work will help identify target treatment goals for the 90 day referendum period, as well as long term target goals and objectives for the project, while remaining compliant to all regulatory requirements.  It is the HBPW's responsibility to remain compliant with both the City referendum and current drinking water standards throughout the entirety of the project.

May 25, 2017

The Hannibal Board of Public Works Board of Directors received the Chloramine Replacement Alternative Evaluation:  Implementation Strategy from Black & Veatch Engineers.  This report identifies target treatment goals, and details concerning the project’s approach, constraints, and delivery. 

To download this report, click HERE. 

May 31, 2017

Black & Veatch Engineers met with the Missouri Department of Natural Resources to discuss the discontinuance of chloramines in Hannibal’s water treatment disinfection system.  In attendance were several Black & Veatch members, several members of MoDNR and State of Missouri, and HBPW’s Utility and Construction Engineer, Mathew Munzlinger. 

To download the Black & Veatch summary of the meeting, click HERE. 

June 7, 2017

Bob Stevenson, General Manager for the HBPW, submitted a project report to the Board. 

You can read the one page report HERE. 

July 25, 2017

On July 25th the HBPW Board Members received a copy of Black & Veatch Engineers Initial Findings Report over the Chloramine Replacement Alternative Evaluation that was proposed to the Board of Directors in April 2017 and approved in May 2017. 

"[This 64-page report] summarizes findings from an initial screening of potential solutions to enable compliance with MCLs for TTHMs and HAA5s once the plant begins operating with free chlorine in place of chloramines.  The initial screening consisted of a comprehensive review of the City's treatment alternatives, distribution system modifications, and potential source water alternatives." 

You can download a PDF copy of the full report HERE

August 9, 2017

Hannibal Board of Public Works staff, Calgon Carbon Corporation and Black and Veatch Engineers installed a small scale Granular Activated Carbon (G.A.C.) system at Hannibal’s Water Treatment Plant.  This unit has four vessels which mimic four different G.A.C. treatment scenarios. The data from these four vessels will guide us in determining which process will be most advantageous in meeting future regulations without the use of Monochloramine disinfection.  This DNR approved Pilot Project will extend for up to six months and plant personnel will monitor numerous parameters at least every 3 hours throughout the length of the Pilot Project.     

The four vessel tests include:

1st vessel - A single G.A.C. vessel

2nd vessel - Two G.A.C. vessels in series

3rd vessel - Vessel mimicking our current filter construction with a G.A.C. cap

4th vessel – Vessel demonstrating            

For photos of the pilot study, go to the Hannibal Board of Public Work's Facebook page. 

October 9, 2017

The HBPW received data from Black & Veatch from the G.A.C. pilot study that was installed at Hannibal's Water Treatment Plant in August 2017.  View the results HERE