Sheetflow Construction Erosion and Sediment Control

October 23, 2019

Concrete Pour

Filed under: Photo — Tags: , , , — Sheetflow @ 1:22 am
Always fun to watch someone else working. Photo: David Jenkins

Here we are constructing a large stormwater pond. To keep vegetation from growing and attracting birds (dangerous to aircraft) the bottom is covered with concrete, the sides will be covered with heavy plastic liner, and the whole thing will be covered with a net. Frequently, on large concrete pours, we specify that there be no truck washout on site, both to speed things up and to avoid concrete mess everywhere.

October 22, 2019

You Don’t Always Need to use Silt Fence

October 21, 2019

“Means and Methods” vs. Best Management Practices

Demolition of landside crane rail on a shipping container terminal.

In my experience, managing contractor “means and methods” is more important than using the “right” best management practices. When turbidity is the standard for measuring water quality compliance, as in Washington state, site cleanliness is the key to prevention and compliance.

This contract requires that catch basin inserts be installed in all catch basins within the project boundaries. However, inserts are not at all effective in reducing turbidity in runoff. While removing the crane rail on this container terminal project, the contractor could clean up as the work progresses, place all material removed from the trench onto plastic for later removal, load into a Bobcat bucket, and pick up small debris with a shop vac. I can require these things in the contract that the contractor bids. It may cost extra; the extra cost may be worth it if it reduces my risk. If I tell the contractor after the contract is awarded, I will pay more.

I can also make suggestions during the work, pointing out that keeping things really clean will keep them in compliance with their NPDES permit. If framed in a way that shows benefit to the contractor, meaning reducing risk and cost, they will probably follow the suggestion.

October 18, 2019

Highway 93 Storm

Filed under: Photo — Tags: , , , , , — Sheetflow @ 1:10 am
Somewhere in Nevada. Photo: David Jenkins

October 15, 2019

Construction Erosion Control Inspection, June 2013

October 12, 2019

Sand Bag Berm to Divert Clean Water View 3

October 10, 2019

Sand Bag Berm to Divert Clean Water View 2

October 8, 2019

Sand Bag Berm to Divert Clean Water View 1

October 6, 2019

Construction Entrance Fail

This is a 30 + acre site with one access point, this one. If this was my project, I would have specified a tire wash with an asphalt exit to the street. The tire wash would have been long enough for two tire rotations, have high pressure, low volume nozzles located such that all tire surfaces were sprayed. This system would also have an on-board, treatment polymer injection system to keep the tire wash water relatively clean. I would have specified that the water be tested for turbidity daily, measured at 50 NTUs or less. Since the water is classified as “process water”, I would have required it to be tested for metals and other contaminants, then hauled to an appropriate disposal facility.
Photo: David Jenkins

October 4, 2019

Broken Waterline

Broken 16 inch waterline. Fortunately, all of the muddy water was contained in a 72″ storm pipe with a valve. Water was then pumped to a Chitosan-enhanced Sand Filtration (CESF) system for treatment to 5 NTUs for discharge to a creek. Knowing this project was going to be constructed over several winter seasons, we specified the CESF system in the contract.
Photo: David Jenkins
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