Thursday, August 7, 2014

Toxic bacteria Cut Off Water in Toledo

On Saturday, August 2, 2014 routine water testing at the Collins Park Water Treatment Plant in Toledo, Ohio had two samples test positive for microcystin at concentrations higher than the standard of 1 microgram per liter for potable water. A “Do Not Drink” order was issued for the city and the residents were without drinkable tap water. On day three the drinking water from Toledo’s Collins Park Water Treatment Plant was declared safe to drink, and life returned to normal in Toledo, Ohio, but is the new normal safe drinking water most of the time.

Microcystine or cyanobacteria is a toxin produced by microcystis, a type of blue-green algae that spreads in the summer algae bloom. These algae blooms are called dead zones and according to a 2013 Canadian and U.S. International Joint Commission report algae blooms had almost disappeared by the end of the 20th century, but there has been a recurrence with some of the worst algae blooms seen in the lake occurring in the last six to eight years. In 2011, the largest mass on record formed in the lake's western basin, eventually reaching more than 100 miles from Toledo to Cleveland, Ohio. That 2013 report stated that urgent steps are needed to curb runaway algae before the toxicity associated with these newer algae blooms impacts water supplies and affects human health, animal health. Last year this was thought to be an extreme scenario.

Dead zones form in summers when higher temperatures reduce the oxygen holding capacity of the water, the air is still and especially in years of heavy rains that carry excess nutrient pollution from cities and farms. The excess nutrient pollution combined with mild weather encourages the explosive growth of algae fed by excessive nutrient pollution. While the algae produces oxygen during photosynthesis, when there is excessive growth of algae the light is chocked out and the algae die and fall from the warmer top layers to the colder depths. The algae are decomposed by bacteria, which consumes the already depleted oxygen in the lower cooler level, leaving dead fish in their wake. Only certain species of blue-green algae form the toxin, for reasons that aren't fully understood. Toxic bacteria were not a problem until the 21st century, though algae blooms have been a problem on Lake Erie for over half a century.

The dead zones in the 1970’s were caused by the release of phosphorus in (what we would consider) partially treated sewage being released into the lake by waste water treatment plants along its shores. Stronger regulations on waste water treatment plants under the Clean Water Act seemed to alleviate that problem to a large extent. However, in the 1980’s the ecology of the Great Lakes began to change, invasive zebra and quagga mussels have disrupted the aquatic food chain and replaced native species. These invaders consume the beneficial types of algae, while rejecting harmful blue-green algae.

The algae blooms are now fed by a wider source of phosphorus. According to the 2013 report different sources of phosphorus runoff have emerged: farms, where manure and other fertilizers are washed into tributary rivers during storms and snowmelt, suburban lawns, septic systems, city streets and parking lots. Though combined municipal sewage systems are still a big contributor to nutrient pollution particularly the Detroit treatment plant, which discharges into the Detroit River a Lake Erie tributary. The nutrient pollution in the Maumee River, which drains agricultural areas of northwestern Ohio and flows into Lake Erie at Toledo, is believed to be agricultural in origin.

In the winter of 2012 The Ohio state Environmental Protection Agency issued two extremely critical reports about the condition of Toledo’s Collins Park Water Treatment plant, which spells out concerns about the system having an "unacceptable risk of system failure." According to a report in the Toledo News Now the Ohio EPA report identified several areas of regulatory non-compliance and significant deficiencies of Toledo's Collins Park water treatment plant. The most serious is what the Ohio EPA calls a "lack of reliability due to age and condition of essential equipment, such as pumps, check valves, impellers and electrical equipment."

Despite constant reminders of the vulnerability of our drinking water supply to contamination of the source water, failure of the treatment and distribution system failures, we have barely thought twice about our water and have taken for granted the capital investment made by previous generations. The water bill that most pay barely covers the cost of delivering the water and some repairs and there seems to be significant resistance to increasing water bills to pay the true cost of water and the systems needed to deliver that water. No infrastructure lasts forever and we have failed to properly maintain and plan for the orderly replacement of the water distribution systems in most places. The water distribution systems in most of our big cities and many of our older suburbs have reached the end of their useful life and water mains are failing at an ever increasing rate. As documented both by this survey and the AWWA, report: “Buried No Longer: Confronting America ’s Water Infrastructure Challenge” the need to replace or rebuild the pipe networks that deliver water comes on top of other water investment needs, such as the need to replace water treatment plants, upgrade treatment technology to respond to emerging contaminants in our raw water supplies, replace storage tanks and on-going monitoring and compliance costs.

Life returning to “normal” is not good enough, the algae bloom is still floating on the lake, but for the moment the Toledo intake is clear. The United States has had one of the finest and safest drinking water supply systems in the world. To keep 42/7 on demand safe water, we need to invest in the system for our future and protect our ecosystem.

No comments:

Post a Comment