New Study: Lawn Fertilizer, Septic Tanks Big Contributors To Great Bay Pollution

May 16, 2013

The study modeled nitrogen inputs from Non-Point Sources, which is to say, it didn't count outflow from waste water treatment plants.
Credit NH Department of Environmental Services

The New Hampshire Department of Environmental Services has released a draft of a major study trying to pin down the sources of nitrogen pollution in the Great Bay Estuary. The results offer some insight, but few easy solutions.

The study says – not counting nitrogen from waste water plants – a third of the pollution flowing into the Great Bay comes from the atmosphere. Atmospheric nitrogen is mostly a residue from the burning of fossil fuels and is gradually declining as federal emission controls tighten. It mostly drifts in from out of state.

But Matt Wood, one of the authors of the study, says the next biggest source is a near tie between private septic systems and fertilizers. Wood says, while dealing with septic systems would be expensive, fertilizer especially on private lawns is low-hanging fruit.

“We really thought that managed turf like golf-courses might have a much larger role to play. And we were really surprised to see it was a very small component,” says Wood.

Wood says today’s take-away, is that individuals and farms using fertilizer more responsibly can have a big and inexpensive impact on the Great Bay ecosystem.