Sheetflow Construction Erosion and Sediment Control

April 19, 2019

On Vacation

Filed under: Photo — Tags: , , , — Sheetflow @ 3:19 am

Checking erosion in Northern Arizona.

North rim of the Grand Canyon
David S. Jenkins Photo

April 18, 2019

On Vacation

Filed under: Photo — Tags: , , , , , , , , — Sheetflow @ 3:18 am

Checking out erosion in southern Utah.

Wire Pass to Buckskin Gulch Slot Canyon
David S. Jenkins Photo

April 16, 2019

On Vacation

Filed under: Photo — Tags: , , , — Sheetflow @ 7:41 am

Checking out erosion in southern Utah.


Paria, Utah
David S. Jenkins Photo

April 9, 2019

Process Wastewater

What is process wastewater?

The definition of process wastewater and how it applies to construction has always been a bit confusing to me.  There are some construction activities that are obvious generators of process water like pressure washing, but then there seems to be some grey when it comes to filling a water truck from a hydrant and using the water for dust control. 

I suspect regulators, if you ask them, will give some conflicting definitions of construction process water.  I am going to try to work through this over a few days, or weeks or however long it takes to come up with a satisfying answer. 

First off, how do the Feds define it? Process wastewater as defined by 40 Code of Federal Regulations (CFR) 122.2. https://www.law.cornell.edu/cfr/text/40/122.2

 it says: “Process wastewater means any water which, during manufacturing or processing, comes into direct contact with or results from the production or use of any raw material, intermediate product, finished productbyproduct, or waste product.

EPA uses this definition in their NPDES Glossary. Find at https://www.epa.gov/npdes

The Washington State Department of Ecology uses that definition in the Construction Stormwater General permit and adds: “If stormwater commingles with process wastewater, the commingled water is considered process wastewater”.

This is the legal definition of process wastewater.  It is a good, solid, bit of legalese, developed by lawyers for lawyers.   Though I haven’t researched this, I think it is likely this definition originated when the Clean Water Act was in its beginning stage of development and was applied to industrial, “end of pipe” discharge facilities, like chemical plants, and manufacturers. 

Herein, I believe, lies my confusion; construction doesn’t fit this description.  I guess technically it is, or can be, an end of pipe facility, but construction is transient, has a limited duration, and generally has the potential for diffuse discharges rather than just one or two discreet discharge points.

With that, I will think some more and post some more when my headache goes away.

April 2, 2019

Migratory Bird Treaty Act Nest Removal

A little something different this week: we are going to do some demolition next to the waterfront this spring. Starting in April or May, seagulls begin nesting on buildings around the waterfront. When seagulls nest, you can’t demolish the buildings until you apply for and get permission for a “Take” of a bird covered under the Migratory Bird Treaty Act. This takes time, holds up the contractor, everyone gets frustrated. In order to head this off, I wrote some contract specifications, which hopefully, will keep this from happening

NESTING BIRD WATCH AND CONTROL

  1. Owner shall provide bird watch services up until 30 days after Contract Execution, to ensure there are no nesting birds that may impact the Contractor’s ability to perform work. At 30 days after Contract Execution, the Contractor shall take over full responsibility for this work.
  2. Contractor shall be responsible for preventing migratory birds from nesting on the roofs of buildings to be demolished. 
  3. Prevention shall include, at a minimum, once daily roof inspections to determine whether migratory birds are conducting nest building activity. 
  4. Nests that do not contain eggs and that are not in the possession of migratory birds shall be destroyed.
  5. Nests that contain one or more eggs shall not be disturbed and shall be immediately reported to the Engineer.
  6. Nests that are complete and in the possession of a migratory bird, with or without eggs, shall not be disturbed and shall be immediately reported to the Engineer.
  7. All Project delays and associated costs due to nesting birds discovered after the Contractor assumes responsibility for bird watch/control shall be the full responsibility of the Contractor.

March 26, 2019

Clouds # 1

Filed under: Photo — Tags: , , — Sheetflow @ 5:33 am

DSCN8785 adjusted bw

David Jenkins-One Click Off Photography

March 19, 2019

Unrolled Asphalt Berm Edge Clean Water Diversion

Here is another cool trick for keeping clean water out of your project. The contractor put down ATB (asphalt-treated base) and asphalt but didn’t roll (compact) the edge, which left a 3 or 4 inch berm. Clean rain water was kept on the asphalt rather than flowing off into the dirt shoulder and disturbed areas.

March 12, 2019

Storm Clouds Over Kanab, Utah

Filed under: Photo — Tags: , , , , — Sheetflow @ 1:32 am

Storm Clouds Over Kanab, Utah

David Jenkins-One Click Off Photography

March 8, 2019

Curb Inlet Protection

According to the Minnesota Stormwater Manual:

“Inlet protection devices intercept and/or filter sediment before it can be transported from a site into the storm drain system and discharged into a lake, river, stream, wetland, or other waterbody.

These devices also keep sediment from filling or clogging storm drain pipes, ditches, and downgradient sediment traps or ponds.

Inlet protection may also include placement of a barrier to create a bypass of an inlet transferring flow downstream to a sediment trap, basin, or other inlet discharging to a non-critical area.”

Nothing wrong with sediment control BMPs, as they are necessary tools in an effective erosion and sediment control system.  However, these do not “filter” sediment. 

When properly installed, these allow for ponding of water which allows larger sediment to settle out, keeping it out of the storm system.  This is a good thing, but doesn’t necessarily prevent water quality non-compliance.   

I do like this statement in the manual : “Caution: To the extent feasible, erosion prevention practices such as stabilization are preferred to sediment control practices.”

In my world, where we have to meet a turbidity effluent limit of 25 NTUs, stabilization and stormwater management are the primary methods used to meet strict turbidity limits.  

March 1, 2019

Managing Construction Projects to Prevent Sediment Trackout

I originally submitted this abstract for the 2019 IECA Denver conference . It was not accepted as a presentation but as an article in the October 2018 edition “Environmental Connection Magazine”.

Abstract
Sediment tracking from construction sites onto public roads and highways is a continual source or frustration for both regulators and contractors. The standard best management practices (BMPs) available, such as stabilized construction entrances and sweepers, often don’t work at all and, at best, only reduce total sediment by 30-50% which is inadequate for preventing water quality violations. In addition to water quality problems, sediment tracking onto roadways can generate dust, which may violate clean air standards and cause unsafe conditions, especially on highways.
This paper will discuss BMPs, methods, and procedures, which can be used by contractors to prevent sediment from being tracked onto roadways in the first place. In addition, ways to significantly reduce sediment loss will be presented. Some of these methods include:

• Passive tire baths
• Various tire washes
• Keeping vehicles of dirt
• Vacuum vs. mechanical sweepers
• Road washing
• Contract specifications

Each method will be discussed with pros and cons, design information and contract specifications.

The full magazine can be found at:
Environmental Connection, October/November 2018, Volume 13, Issue 4.

The article is attached below.

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