Watershed Crash Course
by Nicole Carlozo -- August 31st, 2012
A brief intro on curbing Chesapeake Bay pollution.
Last week I started my fellowship at Maryland’s Department of Natural Resources. Although I’m done with school (for now), I’m still learning about coastal policies, management, and ecological processes. Having earned my Masters along North Carolina’s shores, I find myself in the dark about many of Maryland’s coastal policies and Chesapeake state collaborations. Of course, that’s all about to change.
This week, I braced myself for a crash course on the Chesapeake Bay’s water quality goals and watershed management practices (a very appropriate task during World Water Week, if you ask me). And it all boils down to one thing: Total Maximum Daily Loads.
What are Total Maximum Daily Loads, you ask? Basically, 92 tidal segments of the Chesapeake Bay watershed have pollution caps. Total Maximum Daily Loads (fondly referred to as TMDLs by managers and citizens alike) represent the maximum amount of pollution allowed in each segment while still meeting water quality standards. For the Chesapeake Bay, three pollutants are regulated.
Nitrogen (N), phosphorus (P), and sediment are the major contributors to pollution in the Bay. N and P enter our watershed and encourage algae growth, which in turn depletes oxygen levels and reduces sunlight penetration through the water column.
Pollutants enter the Bay from waste water treatment plants, storm surge, agricultural or lawn fertilizer runoff, and a variety of other sources. Levels are exasperated by shoreline erosion, impervious surfaces/development, and limited vegetation buffers which, if present, would filter these pollutants from the water.
However, Maryland and the other Bay states have chosen to regulate these pollutants to meet the Bay’s water quality standards. Of most concern to managers are dissolved oxygen levels, water clarity, under water Bay grasses, and chlorophyll a concentrations (an indicator of algae).
Believe it or not, these TMDL efforts are relatively new. In response to a 2009 Executive Order, the EPA developed the 2010 Chesapeake Bay TMDL for all 6 Bay states (Delaware, Maryland, New York, Pennsylvania, Virginia, West Virginia) and the District of Columbia. In response, participating jurisdictions developed Watershed Implementation Plans (WIPs) to divide pollution allocations between point and non-point source sectors. [Point sources include facilities like waste water treatment plants where pollution levels can be controlled and monitored. Non-point sources include uncontrolled or immeasurable pollution such as agricultural runoff.]
Recently, a second WIP was developed in Maryland to specify implementation within all five major basins. Every two years, goals (or milestones) are developed so the state will soon meet the TMDL’s overall goal: implementing all water management practices by 2025 that will eventually fully restore the Bay. In the long run, all waters should meet their designated use (i.e. swimming, fishing, etc.) as described in the Clean Water Act.
In short, best management practices are being implemented to reduce N, P, and sediment levels in impaired Chesapeake watersheds. By improving water quality, managers hope to improve biodiversity, habitat and overall estuary health while aiding fisheries, tourism, and recreational Bay activities. Sounds like a merger of science, policy, and economics to me.
Next week, the crash course on aquaculture begins. What can I say? Once a student, always a student.