Linear BMP,s Gravel Bags

So now you've had time to consider Worst Practices, but what about Best Practices? What are Best Practices? Best Management Practices, BMP's are a combination of materials and procedures to minimize sediment and other pollutants from entering the storm drain system. These BMP's can be used singly or in combination with other BMP's. The following is a simple description of basic linear BMP's used to protect areas outside of the construction zone. The first consists of a Gravel Bag Berm, which typically consists of a double high line of gravel bags placed along the perimeter of a project. The objective of this Bag Berm is to slow rain related run-off long enough that the sediments settle or dropout behind the bags, and that only Clear Water runs out of a site. The same objective is achieved using check dams and gravel bag chevrons, on sloped areas with added benefit that the run-off is also slowed down sufficiently to reduce water velocity and therefore the effects of erosion on the slope surface.

As you can see from the pic on the lower right, it is far from a perfect science, but if implemented properly can go a long way to mitigating contaminated run-off.

Also keep in mind that the new EPA standards will be adopted by the revised California NPDES Permit, which in turn means your TMDLs will be much more tightly monitored.

Clear Water Thoughts Tuesday March 24th 2009

Recently I stopped in at a local electronics store and noticed that the adjoining construction site was not protecting the inlets and perimeter properly. I find it interesting that in this day and age, in Orange County that I would see such a poor implementation of basic BMP's. It's one thing to have properly installed BMP's fail when you have a sudden heavy rain, it's another to choose not to properly implement and install them in the first place. The problem is pretty basic, either because of ignorance or neglect this contractor looks like they don't care enough to protect the perimeter and the storm drain system. You say, so what a little dirt goes down the storm drain, along with other pollutants, but do you realize that this dirty water flows straight into the ocean with no treatment. The storm drain system is designed to take away rain water, not construction contaminated rain water. As it stands now, cities, counties, the state and therefor we the people get to pay for the clean up. It costs millions of dollars a year to maintain the storm drain system, a significant part of the clean up is from trash discarded in the street, but a significant portion of the sediments and other chemicals can be traced back to construction. If you know of any particularly nasty sights in Southern California, please share the info here so we can get on them to stop mucking up our world.

Worst Practices 03/23/09

As you may well know the Clean Water Act, and specifically the states NPDES Permit are the guiding documents for Storm Water issues within the state (Ca). I was recently in Orange County Ca, and saw a great example of worst practices, as opposed to best practices. Being a certified erosion & sediment control person, I was absolutely amazed to see the complete lack of understanding of basic controls, and proper implementation. There appeared to be little or no regard for either the environment, the regulations, the construction companies reputation as a polluter or the trade craft of erosion & sediment control. I realize that budgets are beyond tight, but I also realize that failure to implement properly, the most basic of BMP's, Best Management Practices, violates us all. It allows pollutants, sediment and other contaminants to flow into our storm drains and straight out to the ocean. As you probably know storm drains, unlike sewers, have no treatement and flow straight into the streams and rivers and ultimately to the ocean.