Published by Vermont Public Radio
With a surface area of 435 square miles stretched over a length of 120 miles, Lake Champlain is one of the largest lakes in North America. Its waters support aquatic ecosystems, recreation, agriculture and public water supplies.
Percent phosphorous reductions required for each lake segment: The proportional percent of phosphorus reduction required for a lake segment may be quite different from the volume reduction required. For example, in a segment with low phosphorus loads, a small volume may represent a large percentage of that segment’s reduction — and vice versa.
But high levels of phosphorus in the water threaten all these uses of the lake. A plan to clean up Lake Champlain proposes limiting phosphorous runoff, which causes potentially toxic blue-green algae to proliferate. The plan is called the Total Daily Maximum Load, or TMDL.
The limits apply not just to farms and developments (although those are the leading contributors of phosphorus to Lake Champlain), but also to wastewater treatment plants, back roads and even forests and streams. Runoff from all these sources throughout a 8,234-square-mile watershed in Vermont, New York and Quebec ends up in the lake.
A new proposal, referred to as Total Maximum Daily Loads (TMDL), is a choice between scenarios that allow different amounts of pollution from various sources to enter specific parts of the lake. It’s a long and technical document; this series of interactive graphs and charts explains the basics of the official plan — which is not without controversy.
That’s a huge watershed.
It is, indeed!
That’s part of why it’s such a big deal: The ramifications of trying to limit phosphorus runoff into the lake are significant, even for communities that aren’t in close proximity and don’t really consider the lake part of their landscape. So, it’s a lot of communities, and it’s hard for a lot of the members of the public, especially in those far-away places, to wrap their heads around their roles in the issue, and consequently how the proposed solutions will affect them.
Between all the pending changes to managing forests, streams, back roads, farms and development — and wastewater treatment facilities — it’s hard to overstate the magnitude of what’s in store to clean the lake up. But, it’s also hard to imagine the alternative, which is letting super-stinky and potentially toxic blue-green algae to proliferate and choke out major segments of this natural jewel.
That said, it remains to be seen whether the EPA’s proposed limits are feasible. Even by their own calculations, at least a few are not. Some critics of the plan, including environmentalists, have said that many of the goals are essentially pipe dreams.
-Hilary
P.S. Thanks for reading!