DC’s combined sewer area.  Image from DC Water.

The Obama administration’s decision to to pay an impervious area fee added to all water bills in DC, reversing its earlier position, is a welcome step toward cleaner water.

DC Water levies the impervious area charge on customers based on the estimated level of stormwater their properties dump onto the streets and thus into the sewers. This is necessary to pay for replacing DC’s antiquated Combined Sewer Overflow (CSO) system.

Until 1900, the District installed under every street one pipe to handle both sewage and storm water.  Whatever you emptied into your kitchen sink emptied into the same pipe carrying whatever washed along your street’s curbs.

The problem is that our sewer system, much like those in other old American cities, simply cannot handle the sheer volume of water that flows through the sewers during heavy rains.  As a result, the sewers overflow into Rock Creek, the Potomac, and the Anacostia at 53 outfall points during these storms.  As you can imagine, this discharge is neither safe nor pretty.

Rather than dig up every 18th- and 19th-century neighborhood street, DC Water is building several huge containment tunnels to temporarily store sewage-storm “brews” until the treatment plant at Blue Plains can process it all after the storm.

DC Water’s CSO plan.

Underground storage tunnels will cost $2.2 billion. To recoup this cost, DC Water started levying a fee on all impervious surfaces on customers’ properties, regardless of whether the property is located in a combined sewer area. 

Impervious surfaces, such as a house’s footprint or a driveway, prevent the ground from absorbing rainwater and slowly releasing it through local springs. Instead, water runs off our roofs, into gutters, down the downspouts, onto a sidewalk or driveway, into the street and then into the sewer.  Consequently, storm drains on the street aren’t just handling street water, they’re also handling the water our homes, offices, parking lots, and driveways dump on the streets.

DC Water is working with the DC Department of the Environment to discount the fee for properties that mitigate their runoff.  Until then, we’re all paying for our runoff and the tunnels that must contain it.

But is it a fee based on usage, like your water bill, or is it a tax, like a property tax?  As you learned in your civics class, no state, and certainly not the District, may tax the Federal Government.  The Feds will pay for services provided, such as water and electricity, but they will not pay property and other taxes.

Since this fee is structured to approximate your burden on the sewer system, it shouldn’t count as a tax. The Obama administration at first disagreed, arguing it was a tax and that the federal government should not pay.

Most ironically, DC Water’s tunnels are being built to comply with the federally-mandated Clean Water Act.  In essence, the federal government contributes to the problem, mandates a solution, but refuses to pay for it.  This is worse than an unfunded mandate because federal government properties are partly responsible for the problem in the first place.

Without the federal government paying its share, which accounts for 20% of impervious area in DC, water bills for DC residents would soar to compensate for the Feds’ “principled” delinquency.  One can imagine residents demanding DC Water shut off the water to all government properties; it’s hard to stand on principle if it means sitting in a porta-potty.

Congresswoman Eleanor Holmes Norton (D-DC) and Senator Ben Cardin (D-MD) are more diplomatic. They are sponsoring legislation to require the Federal Government to pay.

Fortunately, after a second look, and probably after some hard lobbying, the Government Accountability Office reversed its earlier decision.  In a recent letter DC Water provided us, GAO states, “We have concluded that the [Impervious Surface Area] charge is a component of the utility rate customers pay for water and sewer services.”  That is, the impervious area charge is an integral part of financing a sewer system, that by law must comply with national water quality standards.