Requiring pricier septic systems is divisive point in springs protection

Published Nov. 10, 2007
The county's ordinance calls for new septic systems that would reduce nitrogen in septic tank effluent by 70 percent, or down to just 10 milligrams per liter.

In contrast, traditional septic tanks don't break down nitrogen at all, said Dale Holcomb, Florida Department of Health environmental administrator. Instead, most of the chemistry happens in their drainfields, where helpful bacteria in the soil and plants break down only about 30 percent of the nitrogen.

But that still leaves 70 percent left to slip dangerously into groundwater and the springs where algae and aquatic plants await their next meal.

The proposed ordinance aims to curb swelling levels of nitrogen in the Rainbow and Silver Springs.

The level of nitrates in the Rainbow River has doubled in the past 10 years and increased five-fold in the Silver River during the past 50 years.
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