Monday, August 24, 2015

Profitable Green Canopy and Stormwater

Let’s expand our green canopy in the upper regions of the Clinton, Rouge and Huron watersheds. Trees generate oxygen, capture carbon and absorb water. Tree roots also guide excess surface water down into the ground.

New York City, Philadelphia and Los Angeles already have plans to plant one million trees in 10 years, mostly with tax dollars, volunteers and philanthropy. What I have in mind for southeast Michigan is a different  model.

Overlooked by many green infrastructure advocates is that some trees have commercial value other than lumber.  We could increase the canopy and simultaneously create or expand commercial fruit orchards, Christmas tree farms, sugar maple groves, nut tree groves and ornamental tree nurseries, in addition to native woodland stands.
Image result for apple orchard

Chestnuts are grown as a cash crop in west Michigan.  Why not here in southeast Michigan?  In California, the meatier English walnut variety is grafted to native walnut rootstock.  Why not here?   

Growing trees for profit requires lots of water, a resource California and other southwestern states are running out of.  Michigan has a water advantage, and we should make the most of it.

If 120 communities in the Great Lakes Water Authority system each committed to planting 1,000 trees per year, we’d have a million more trees - and a magnificent canopy -  in less than 10 years. And if done as I suggest, the project would eventually pay for itself twice, first in stormwater control savings and second in cash crops.

Tuesday, August 18, 2015

Silt Enforcement Hypothetical

Suppose there are 8,000 active residential construction sites in southeastern Michigan this spring, summer and fall, all on average-sized city lots, all having excavations for basements with the corresponding piles of dirt.  Also suppose that there are 3,000 large commercial, industrial, public works or utility projects, each having disturbed the soil to a significant extent.

Further, let’s assume that on half of all such construction sites, no erosion controls have been applied, and on the other half, silt fence has been installed but not maintained; and after being run over by trucks, front-end loaders, skyhooks and the like, the silt fence no longer functions.

Say the weather is in the typical range with three major rainstorms over the construction season at any given site.  Assume further that during each of those heavy rains, each residential lot loses one ton of loose soil (equivalent to a pickup truck load) in runoff which flows into sewers, and each of the large commercial, etc., projects loses three tons.  Then, after three heavy rains, a total of 51,000 tons (51,000 pickup truck loads) of dirt have gone into sewers.

Unlike many cities the size of Detroit or larger in the past decade or so, insolvent Detroit was not required to build a huge tunnel to hold billions of gallons of storm runoff for gradual release, screening, settling and treating.  

Instead, in our region, a deluge that causes silt-laden water to surge from construction sites into sewers also causes the sewers and a handful of small retention basins to overflow into local ditches and streams, which feed international treaty waters like Lake St. Clair, the Detroit River and Lake Erie.

That means, in our hypothetical, during each construction season, 51,000 tons of eroded soil clog the sewers, cloud our natural waterways, and fill the bottoms of rivers, harbors and lakes with sediment.

Image result for vactor 2100Silt fence at Lowe’s costs construction contractors around $30 for a 100’ roll. (Two or three well placed rolls would probably suffice on most city lots).  Thus, if local (county or city) erosion control enforcement agencies forgo strict requirements for silt fence (paid for by contractors) in preference for county or city sewer vacuum trucks like the Vactor 2100 (at $350,000 to $400,000 each) to suck the mud out of sewers, the needless cost to taxpayers is inexcusable.  

Something’s wrong with this picture.

[Readers: Got better numbers?  Leave a comment.]

Wednesday, August 12, 2015

Janicki Sewage Processor Up & Running in Africa


Photo via Gates Notes/The Janicki Omni Processor in Dakar, Senegal

Does a pilot project in Africa hold promise for cheaper, more efficient sewage disposal in southeast Michigan?  Imagine a number of these machines scattered throughout our region, eliminating the need for miles and miles of interceptors, as well as the Detroit wastewater treatment plant; not to mention landfills and the NEFCO pelletizing plant presently necessary for sludge disposal.

Molly Brown (August 12, 2015 on GeekWire) describes the success of the inexpensive Janicki sewage processor, funded by Bill and Melinda Gates’ foundation, in Dakar, Senegal (excerpts):

[Bill Gates’ blog, Gates Notes]...shows how the Omni Processor takes one third of the sludge in Dakar [population 1.2 million] and makes it into potable water, electricity and ash.

Even greater news? Gates reports in his blog that this is only the first iteration of the project, which has allowed them to fix a few engineering problems and set their sights on a much bigger and better use — garbage.

Gates calls the results “promising” and that his team is “still looking at ways to make the [Janicki Omni Processor] cheaper and smaller.”

“Now we have a business plan, an impassioned team of engineers, great in-country partners, and a pilot project in motion,” he concludes in his post.