Archive for October, 2010

October 4, 2010

Improvements Since ’93 Des Moines Floods

The Raccoon River was above flood stage in Water Works Park seven times in 2010.  Even though record high flood levels were not reached, all that water creates a lot of work and makes us wonder what the future will bring.

In 1993 the levee surrounding Water Works’ Fleur Drive Treatment Plant was overtopped by flood waters, leaving the Des Moines without water for more than a week.  Since then a number of projects have been completed to help ensure this does not happen again.

Most importantly, the levee surrounding the Fleur Drive Plant has been raised by six feet to a level four feet above the record 1993 water level.  A flood gate has also been added which can be closed quickly as compared to the earthen plug that was used to close the levee in the past.  These improvements have not seen water as high as 1993 but they were tested during the flooding in 2008 when more than 8 feet of water rose against the 14-foot tall flood gates.  The levee and flood gates performed well and treatment plant facilities were protected.

In addition to levee and flood gate improvements the Water Works has added additional sources of supply since 1993.  In 2000 the LD McMullen Water Treatment Facility went into service near Maffitt Reservoir with the ability to produce up 25 million gallons of water per day.  Four aquifer storage and recovery wells have also been constructed around the metro with a combined capacity of over 10 million gallons per day.  Later this year the new Saylorville Water Treatment Plant will go on line with the capacity to supply up to an additional 10 million gallons per day to the metro area.  Taken together these facilities provide valuable backup to the primary Fleur Drive Water Treatment Plant.

All of these changes have helped protect the water supply but Water Works Park is still vulnerable to flooding.  Just this year the high water has caused tens of thousands of dollars of damage to park roads, plantings, and other park facilities.  Each time the water level goes above flood stage the cleanup effort in the park requires hundreds of man hours to complete.  In addition high water resulted in the cancellation or relocation of numerous events scheduled on park grounds including concerts, cultural festivals, and family gatherings.

Posted by: Ted Corrigan No Comments
Labels: , , , , , Posted in Environment, Flooding October 4, 2010

Fluoride in Water – First in a Series of Five

The history of fluoridated water is like many of the great scientific findings throughout the ages. It started with an observation.

Archeologists have long known that tooth decay is a modern problem that was rare until the Renaissance, when refined sugar became available to wealthy people. The problem reached epidemic proportions during the industrial revolution, when income levels grew to the point that sugar could be purchased by nearly everyone in an industrialized society.

During the 1870s, scientists and physicians began to notice that people living in some areas of the world seemed immune to tooth decay. Many of these same people also had brown-stained teeth. One of the first cities where this was observed was Naples, Italy. Medical examiners on Ellis Island also noticed many Italian immigrants with this same phenomenon. Similar observations were made in the American West, especially amongst miners in the gold fields of Colorado. It was eventually determined after many years of study that the water these people were drinking contained very high levels of naturally-occurring fluoride, which found its way into groundwater wells via the mineral deposits of the local area.

Researchers determined that these people were getting too much fluoride, and this caused the brown staining which is now known as dental fluorosis. The water they were drinking contained as much as 30 parts per million (ppm) of the element. Studies eventually determined that the optimum drinking water concentration which delivered protection from cavities but did not produce fluorosis was about 1 ppm.

Water intentionally fluoridated at the 1 ppm (parts per million) level was first produced in four cities in 1945: Grand Rapids, MI; Newburgh, NY; Evanston, IL; and Brantford, Ontario. These trials were overseen by an eminent scientist of time, H. Trendley Dean. The results were profound: a 40% reduction in cavities in four years, and up to 57% within 15 years.

It was near the end of this 15-year study, in 1959, that Des Moines Water Works (DMWW) began fluoridating water delivered to Des Moines and surrounding areas. Natural levels of fluoride are supplemented during treatment so that water leaves the treatment plants with the optimum level of 1 ppm.

This article is the first in a series of five articles addressing the subject of fluoride in City water. Please leave a comment, and come back to read the next articles in the series. Thanks for reading!

Posted by: Chris Jones 9 Comments
Labels: , , , , , , Posted in Fluoride, Health, Water Treatment