Maryland just released their draft of a revised erosion and sediment control manual. Included is the use of flocculants to control erosion and to treat for turbidity. Turbidity has been pretty much ignored by mainstream sediment control, as it can not be controlled by traditional traps and filtering methods, especially in runoff from clayey soils. Several other states have already included flocculants as a construction phase Best Management Practice (BMP).
We are ramping up to provide technical and design services and products related to flocculants throughout the Mid-Atlantic in the futuire. Look for a new site, www.floccs.com, as we get closer to going to market.
Steve and Seva Iwinski of Applied Polymer Systems, Inc. have done much groundbreaking work in this field and have been a great help. We look forward to becoming a distributor of their products. Steve has shared a pretty impressive video on flocculants. Check it out:
More to come in the future about this exciting technology.
Our friends at Hord | Coplan | Macht kindly extended an invitation to present an overview of the forthcoming regulations and design guidance in Maryland that requires the application of Environmental Site Design (ESD) on all projects. This is a turning point for stormwater design and represents a significant change in how sites will be designed in Maryland.
Overlooking the Baltimore Harbor on a rainy day – no better place or time to talk about stormwater management! Many HCM clients and staff attended – it was a very productive couple of hours. Check out the presentation:
We are already working on projects under these new regulations, which will go into effect in May, 2010.
Contact us here if you’d like to have a group that would be interested in having us present this information.
This last year when we were in Arizona, we posted thoughts from a purely East Coast perspective. Read it here.
Interestingly, we just happened upon a very comprehensive video of Arizona’s appraoch to managing stormwater in an arid environment. For stormwater fans, it is well worth the 40 minutes viewing time.
The Annual Baltimore Waterkeeper Trash bash is this Saturday at Nick’s Cafe in Baltimore. Last year it was a blast and they are cranking it up this year even more. Should be quite the party! Come join us!
More info at: http://www.baltimorewaterkeeper.org/events/upcoming-events/
A common conventional method for managing stormwater is a stormwater basin. Basins are meant to collect stormwater and slowly release it at a controlled rate so that downstream areas are not flooded or eroded. While effective for flood control, these practices have significant limitations for water quality treatment and for preventing impacts to stream systems.
Detention (dry) basin
The main difference between a detention and a retention basin is whether or not it has a permanent pool of water – like a traditional “pond”. The water level is established by the low flow orifice. Most of the time the orifice is part of a metal or concrete structure called a riser. A detention, or dry, basin has an orifice level with the bottom of the basin so that all of the water eventually drains out and it remains dry between storms – hence, a dry basin. Retention basins have a riser with an orifice at a higher point so that it retains a permanent pool of water.
Retention (wet) basin
The basins themselves are important for storing and slowing (attenuating) the runoff from impervious surfaces such as rooftops or pavement. The amount of treatment, or cleaning, of the water is limited. Dry detention basins control flood flows only. A retention basin can also provide water quality benefits by reducing sediments and attached pollutants.
Shanghai
