What’s on your mind this weekend, Bleeding Heartland readers? This is an open thread.

If you’re among the roughly half a million Iowans whose household water comes from the Des Moines Water Works, you may have noticed a stronger chlorine smell lately. After the jump I’ve posted a statement explaining why the recent snow melt led to elevated ammonia levels in the Raccoon and Des Moines Rivers, the sources for most drinking water in central Iowa. I also enclosed background on the most common causes of higher ammonia levels in surface water systems. Those can differ from watershed to watershed, but in Iowa conventional agriculture is a common source.

The Raccoon River Watershed Association is organizing an “Aldo Leopold Weekend Event” at the Hotel Pattee in Perry this Friday night and Saturday. I’ve enclosed the program below. On Saturday afternoon people will be reading from the Sand County Almanac before a showing of the documentary “Green Fire: Aldo Leopold and a Land Ethic for Our Time.” That movie is well worth watching for anyone who cares about the environment.

TASTE AND ODOR EPISODE DUE TO RUNOFF FROM RECENT SNOWMELT

Thursday, February 20, 2014

Des Moines Water Works uses both the Raccoon and Des Moines Rivers as water sources. By using surface water, seasonal variations can occur. The recent warm-up in temperatures has caused increased runoff into our water supply, requiring Des Moines Water Works to use more chlorine to achieve the desired chlorine levels in the finished product.

Both rivers are currently experiencing elevated levels of ammonia. Disinfection with chlorine is more difficult when ammonia is present in source waters. Ammonia consumes chlorine, leaving it unavailable for disinfection. This requires addition of extra chlorine to eliminate the ammonia and maintain adequate disinfection. For these reasons, chlorine levels have been purposefully higher for the past three weeks. Chlorine levels in the water leaving Des Moines Water Works’ treatment plants are monitored continuously to ensure they do not exceed the maximum allowable limit set by Environmental Protection Agency (EPA).

Finished drinking water from Des Moines Water Works is safe to consume. Some people are more sensitive to these subtle changes in taste or odors. These conditions will improve as the weather stabilizes and levels of runoff decrease.

About Des Moines Water Works

Des Moines Water Works (DMWW) is a municipal water utility serving the citizens of Des Moines and surrounding communities – approximately 500,000 customers. DMWW is an independently operated public utility with a commitment to leading, advocating and investing today and in the future to deliver water you can trust for life.

Excerpt from a post by Iowa State University faculty John Sawyer, Department of Agronomy and Matt Helmers, Department of Agricultural and Biosystems Engineering:

Ammonium and ammonia in surface water systems can originate from many sources, and are naturally occurring forms of nitrogen. Predominant sources will vary on a watershed or sub-watershed basis. Also, sources and concentrations are greatly influenced by hydrology, including timing and volume of water runoff.

It is difficult, if not impossible, to separate the effects of both source and hydrology. This makes the issue of ammonium and ammonia in surface water systems complex and can complicate implementation of practices to moderate movement to water systems. Of main importance is targeting sources or practices that have the potential to significantly reduce delivery to a surface water system. Equally important is that management practices need to vary depending upon specific situations.

Following is a list of possible sources of ammonium and ammonia in surface water systems. These are in no particular order, and are not ranked in order of importance or greatest possible impact. There are likely other sources not listed.

Land-applied manure and biosolids, septic systems, raw sewage, snow, rainfall, animal feedlot runoff, surface runoff into tile inlets, eroded soil and sediment, airborne ammonia, direct deposit by aquatic organisms, wildlife manure, land-applied fertilizer (ammonium containing) for crop and turf production, fertilizer on sidewalks and driveways, manure storage structures, manure stockpiles, manure spills, fertilizer facilities, fertilizer spills, decay of aquatic organisms and organic materials in water. […]

Quite interestingly, because snow readily absorbs ammonia, it can have quite high concentrations of ammonium/ammonia.

Life in the Raccoon River:

The People of the Watershed

(An Aldo Leopold Weekend Event)

February 28, March 1

Hotel Pattee, Perry Iowa

Friday, February 28

7:00 p.m. –Ty Smedes, Nature Photographer-Eagles of Iowa

7:45 p.m.-RRWA Insect Photo Competition Awards

Saturday, March 1

9:05 –10:00  Dr. Mary Skopec, –Current Issues

10:05  to 10:50  Andy Rupiper—Indicators of Biological Integrity  

10:55 – 11:40  Cherie Haury-Artz–Those Who Have Gone Before

11:45 – 12:30  Steven Witmer–The Settlement of the Raccoon River Watershed

Lunch Break

1:30 –2:00   Readings from Aldo Leopold’s Sand County Almanac

2:00 to 3:15: –Video –Green fire: Aldo Leopold and a Land Ethic for our Time