Monthly Archives: June 2016

Environment

Toxic Chemicals Taint 8 Alabama Public Water Systems

Great Blue HeronRecently, the EPA set a stricter health advisory for toxic chemicals perfluorooactanoic acid, or PFOA, as well as for perfluorooctane sulfonate, or PFOS, once made or used at factories near, and thereby affecting 8 Alabama public water systems.

Residents and businesses in the affected area are scrambling to procure bottled water for their families and customers this summer, as a $4 million temporary filtration system isn’t expected to be completed until September.

The Wall Street Journal reports, “Factories for decades used PFOA as a plastic coating to make consumer products such as Teflon nonstick pans, waterproof jackets and pizza boxes. PFOS was used to make stain resistant carpets and other products. A multiyear medical study in the 2000s of 70,000 people near a plant in West Virginia that made PFOA found “some suggestions” of “probable links” between high exposure to the chemical and illnesses, including cancer. Studies have found PFOS to be harmful to the immune systems of animals.”

After long-term exposure to these toxic chemicals, what does this mean for area folks with gardens, restaurants, families? How will this affect the natural balance of wildlife in the area?  We have no answers; only time will tell.

Read more at the Wall Street Journal

Read more at Alabama.com

Photo credit: A great blue heron on the Tennessee River. (Photo by Beth Young, courtesy Tennessee Riverkeeper)

Rainwater Catchment

Building a Potable Rainwater Collection System

sun-11129_640There are several stages to building a successful, potable rainwater collection system. Here is an article originally published in June 2014, under the title Ultraviolet Light Disinfection For Rainwater Harvesting. (Also see “How to Build a Rainwater Collection System, parts one, two, three, four, five, six, seven and eight.)

The final stage of treatment for a potable rainwater collection system is ultraviolet light disinfection (UV). Effectiveness of the UV system is determined by a few factors.  First, pre-filtration, which includes a sediment filter and a carbon filter that need to be upstream of the UV. This will help ensure the clarity of water entering the UV chamber, enabling the UV rays to penetrate the water stream.

When UV energy is absorbed by the reproductive mechanisms of bacteria and viruses, the genetic material is “rearranged” and can no longer reproduce, with risk of disease eliminated.

There are 2 classifications of UV light determined by the dosage of the UV light itself, and a class “A” UV is the only class recommended for disinfection of rainwater collected from a rooftop.

The American Water Works Association describes a class A ultraviolet system as an effective method of disinfection for water that is not determined safe to drink. A class B ultraviolet system is only effective for water already deemed safe to drink – such as a water source already treated with chlorine.

An alarm and or solenoid valve for system fail safe is always a good idea to include with your UV system. This method will shut down the system or sound an alarm if a sensor determines the water turbidity (clarity) is not sufficient for proper UV absorption.

Ultraviolet light is a natural, cost effective environmentally safe method of disinfecting drinking water as long as it is properly maintained and the bulb is changed according to manufacturer’s recommendations.

As always, before you take on a rainwater harvesting project, know the rules in your state, county and municipality. It helps to work with a RWC pro who can help you through the process, saving you time and money along the way, while also ensuring that the result is a functioning and safe water collection system that will serve you for many years.