(CNSNews.com) - Massive quantities of algae are now blooming in the Lincoln Memorial Reflecting Pool, where the federal government has just spent $34 million in stimulus money to make the pool "sustainable" and "improve the quality and appearance of the water."
"Action is needed at this time to address substantial repairs and structural deficiencies at the Reflecting Pool," said an environmental assessment published by the Department of Interior in 2009.
"Engineering analysis has shown that differential soil settlement has compromised its structural system," said the assessment. "The stress on the foundation, joints, and coping has caused pervasive water leakage, which along with evaporation, constitutes a substantial loss of water. This net loss represents a tremendous inefficiency since the NPS [National Park Service] uses the water from a municipal source, the D.C. Water and Sewer Authority (DC WASA). As a result, the NPS needs to improve the efficiency of the system by creating a more cost effective and sustainable method to fill and discharge the Reflecting Pool while at the same time improving the quality and appearance of the water."
Now, just a month after the project was completed, the National Park Service says it is adjusting ozone levels to try to kill an unsightly algae bloom that has occurred in the new environmentally friendly reflecting pool.
"We did not expect this magnitude of algae but we’re now dealing with it,” said Carol Johnson, an NPS spokesperson.
Johnson told CNSNews.com the algae bloom is simply a "maintenance problem," not a failure of the multi-million repair project.
“The algae cells came in from the Tidal Basin, and since this is a new filtration system -- very unique, and in fact, one of a kind -- we knew that we were going to have some balancing that needed to be done, and we weren’t quite sure about what level of ozone we would need to disinfect the water completely,” Johnson told CNSNews.com.
“The important thing that I keep telling people is that I know it is unsightly, but this is a maintenance problem, but it’s not a failure of the project or anything. We’re saving 32 million gallons of drinking water a year because of this restoration,” Johnson told CNSNews.com.
“It’s not a health hazard, it’s just something that we’re going to have to play around with the system until we get it right,” she added.
According to the National Park Service, the old pool--completed in 1924--held about 7 million gallons of potable (drinking) water, much of which evaporated or continually leaked out. The leaks forced regular purchases of drinking water from the District of Columbia.
Moreover, because the water in the old pool did not circulate, "On occasion...the pool would emit a foul smell in August, and at times become unhealthy for waterfowl," NPS says on its website.
The new pool is filled with re-circulated, non-potable water that is filtered and pumped in from the nearby Tidal Basin. When the pool needs to be cleaned -- bird droppings are a major problem -- the water can be "returned to the Tidal Basin," NPS said.
Ozone (O3), an unstable form of oxygen, is used to disinfect water. The third oxygen atom readily combines with organic and inorganic molecules to destroy or change them through a process called oxidation.
Johnson said the ozone level when the pool reopened “was not high enough” to prevent the algae from establishing itself.
“We now have adjusted the ozone levels and it does appear to be working. A lot of the algae is dying.”