A Penny a Day Keeps Cultural Eutrophication Away

The problem with the Marco waterways is that nutrients (phosphorus and nitrogen) from partially treated sewage are feeding an algae population which results in a toxic waterbody and a decline in oxygen levels.

The water in the canals and bays of Marco Island contain algae that are harmful to human health, depresses our property values, drives away aquatic life, blocks sunlight and kills seagrass. Other than that, everything is fine.

The variable cost of removing these nutrients from the reuse water that carries these offending nutrients is estimated to be $10 per pound. There is an upfront capital cost but here we assume this is covered by a grant.

There are about 40,000 pounds of phosphorus and about 60,000 pounds of nitrogen introduced into the Marco waterbody each year from the reuse water from the wastewater treatment plant. The annual cost to remove phosphorus would then be $400,000 and the annual cost to remove nitrogen would be $600,000. The phosphorus would be recovered and recycled.

The population of Marco is estimated to be 16,521 full time residents with a peak population of 40,000 people in the high season. Assume an average population of 28,000 people.

“A penny a day” was a reasonable slogan in the early 70s. The estimated cost of removing phosphorus as a first step in our restoration process is 10 cents per person per day. I think we can afford this. Let’s get started.