More than 100,000 homes on Cape Cod in Massachusetts use onsite septic systems to treat wastewater. In Cape Cod's sandy soil, those systems accomplish little treatment of the effluent — instead, the bulk of the nitrogen flushed into them streams quickly through groundwater flows into the nearby estuaries, the bay, or the ocean, where it helps to cause algae blooms and fish kills. In July, for example, residents reported foul odors in Little Pond, an estuary near Falmouth, Mass., then discovered the carcasses of mature striped bass washed up on shore that had died in the oxygen-depleted water ("Falmouth official: Fish kills a ‘wake-up call'," by Sean Teehan).

But is that a federal matter? According to Boston-based Conservation Law Foundation (, it is — and the foundation is suing the United States Environmental Protection Agency (EPA) to force the agency to throw some paperwork at the problem of septic system emissions, and to hold back federal funds from towns and state agencies until they act to correct it.

The lawsuit is moving ahead this fall, reports the Barnstable Patriot ("WASTEWATER: Key arguments made in federal suit," by Patriot Staff). One key legal point is whether the thousands of independent in-ground septics should be classified as point sources of pollution under the Clean Water Act of 1972. The Construction Law Foundation says yes, arguing in their legal brief, "In effect, these sources are discharging nitrogen directly into the bays through an intermediary (i.e., the highly permeable and fast-moving groundwater) – the equivalent of an underground pipe."

But the EPA says no. "EPA argues that the Clean Water Act is clear that it covers the navigable waters of the United States, and groundwater cannot be considered navigable waters," the Patriot reports. "The one exception is for groundwater that is hydrologically connected to surface waters. EPA said that CLF could make such claims on an individual basis for each septic system or treatment plant, but cannot make a blanket re-categorization of all such systems on Cape Cod." From the EPA court filing: "Plaintiffs are free to file citizen suits against sources to try and establish that they should be subject to federal permitting requirements, but they may not, through the back door of these TMDLs [Total Maximum Daily Loads], seek to apply a whole new regime of federal permitting requirements to virtually every homeowner and business on Cape Cod, 130,000 at a time."

If the suit were to succeed, what would that mean for the 100,000-plus septic systems on the Cape, and the property owners responsible for them? That's not clear. But according to a report in the Cape Cod Times ("Group amends Cape Cod wastewater suit," by Patrick Cassidy), any publicly provided solution will not be cheap. Writes the Times, "Local planners estimate that fixing the problem through the construction of sewers or the use of other technologies and strategies will cost between $4 billion and $8 billion over the next several decades."