Of Trees, Stormwater and Boondoggles

The Detroit Water & Sewerage Department (DWSD) spent years in collaboration with the Southeast Michigan Council of Governments (SEMCOG) getting ready to plant trees in Detroit neighborhoods and parks as part of a larger plan to control combined sewer overflow.  Scores of meetings were conducted and thousands of personnel-hours expended. DWSD contracted with Greening of Detroit, a non-profit organization, to do the actual planting.  

In a typical year like fiscal 2012-2013, approximately 1500 trees were planted over several weeks in the fall and another 1500 over several more weeks the following spring.  

All three organizations knew or should have known that, at the rate of 3000 or so trees per year, they wouldn’t even be replacing the trees in the watershed that are lost every year through blight, wind, rot, insect infestation, lightning and old age.  

Thus, combined sewer overflow (the justification for the project) is not reduced by a single drop.  I would love to see what the actual total cost of this boondoggle is.

The inclination of DWSD, SEMCOG and Greening to plant trees sparsely along residential streets and in city parks suggests to me that those organizations are more interested in the decorative value of planting trees, much like the city’s discontinued neighborhood beautification program, only now it’s being paid for by DWSD’s ratepayers, as well as taxpayers generally.

Compare the work done privately by John Hantz of Hantz Woodlands.  He, too, spent several years jumping through hoops to get his tree planting project approved by the city. He assembled some vacant city lots, rounded up 1200 volunteers and on one Saturday last month, planted 15,000 trees.

Impressed?  Then look at this.   A private-public partnership in New York City had anticipated planting 100,000 trees per year with a goal of one million trees planted by 2017.  But they’re almost at 900,000 now, so they’ve reset the completion date to 2015.  Granted, Detroit is no New York City, but consider how NYC did it.  They organized with the help of one auto company (Toyota), several foundations and a very active celebrity.  Detroit has all of that and more.  It’s just a matter of how it’s put together and by whom.

We deserve a bigger bang for our buck.

DWSD and Polluted Storm Runoff

Using Green Infrastructure to Reduce Combined Sewer Overflow

One of the principal functions of the Detroit Water & Sewerage Department (DWSD) under its NPDES permit is to control combined sewer overflow (CSO) following rainstorms.

Combined sewers carry both human waste and storm runoff.  Heavy rains cause flow in these sewers to overwhelm wastewater treatment plants.  The polluted effluent then contaminates lakes and streams, threatening public health and damaging the environment.

In some large metropolitan areas, huge underground reservoirs or tunnels have been built to hold polluted storm runoff until the treatment plant catches up.

Several years ago, such a reservoir was contemplated for Detroit, but the city couldn’t afford it.  The plan was scaled back, but not enough to be within the city’s ability to pay for it.

State regulators worked with local officials to develop plans for a number of smaller, surface containment facilities.  They would hold the initial, more contaminated runoff (so-called “first flush”) until the treatment plant could provide both stages of treatment, disinfection and solids (sludge) removal.

Under this last plan, the remaining storm surge (after the first flush) would be disinfected and released to public waters without removing most of the solids.  Nutrients in the solids generate algae growth which in turn depletes oxygen downstream.

In addition, the plan to control overflow called for the application of enhanced natural processes to absorb or at least slow down storm runoff.  These processes are commonly known as “green infrastructure.”

State officials included short, vague references to green infrastructure in DWSD’s proposed NPDES permit renewal.  Green infrastructure was intended to reduce CSO by 10 to 15 percent.  (In my opinion, green infrastructure has the potential for much greater CSO reduction than that.)

The Southeast Michigan Council of Governments (SEMCOG) was enlisted to assist in fleshing out more precise detail concerning green infrastructure.  The effort got off to a slow start, but environmental organizations, notably the Sierra Club, helped to keep the project on track.

Today, as the result of city-wide publicity and neighborhood organizing, some of this green methodology is being implemented.  Trees are being planted, downspouts disconnected from sewers and rain gardens established in backyards and on roofs.  Soon, we can expect to see roadside swales created and pervious concrete used for roads and parking lots.  

Some suburban communities have been reluctant to adopt measures like these, but public interest in clean waterways and stable water services rates will drive improved storm runoff control.

DWSD's Wastewater Process, History and Regulation

Perhaps the best summary (16 pages, including charts and maps) of wastewater treatment at DWSD, the city department's record the past few decades and how the State of Michigan enforces state and federal clean water laws can be found on the website of the Michigan Department of Environmental Quality (MDEQ):

http://www.michigan.gov/documents/deq/deq-wrd-npdes-DetroitWWTP_FS_415425_7.pdf

Excerpts:

"The sustained peak primary treatment capacity for wet-weather flows is 1,700 [million gallons per day (MGD)] and the sustained peak secondary treatment capacity for wet-weather flows is currently 930 MGD... All dry-weather flows and a significant amount of wet-weather flows receive full secondary treatment at the WWTP."  (p.3)

"There is currently no additional space at the plant where additional secondary capacity could be constructed. The DEQ has determined there are no feasible alternatives for providing secondary treatment to flows greater than 930 MGD."  (p.4)

[The National Pollution Discharge Elimination System (NPDES) permit] "... focuses on addressing three major issues. The first is providing effluent limits, solids handling requirements, and improved operations and maintenance through a robust Asset Management Program... The second is a reduction in the permitted total phosphorus loads to help reduce phosphorus loadings to Lake Erie. There are numerous sources of phosphorus loadings to Lake Erie, including the Detroit [Wastewater Treatment Plant (WWTP).]  Loadings reductions from point and nonpoint sources are likely needed to help reduce harmful algal blooms in Lake Erie.  The third is a new adaptive management [Combined Sewer Overflow (CSO)] Control Program that recognizes the significant achievements of the Detroit CSO Control Program over the last 20 years, sets forth schedules for completion of the core CSO Control Program, expands the use of Green Infrastructure, and moves forward with the remainder of the control program..."  (pp.10-11)

"The Detroit WWTP has had periods of violations of its NPDES Permit limits and conditions over the past 35 years...After one period of violations from 1997 through 1999, a second amended consent judgment was issued in 2000. These violations largely resulted from high solids inventories accumulating at the WWTP.  The high solids inventories resulted from ineffective operations to dewater solids and remove them from the WWTP...Violations again started in September 2009 and continued until November 2011...As was the case in the late 1990s, the immediate cause was high solids inventories in the WWTP."  (p.11)

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It may be as complete a picture of DWSD as you can get, as long as you overlook a page full of high crimes and misdemeanors.