The Dallas Green Zine

I’ve been using 3 rain barrels to collect water off my composite roof via a regular roof gutter system. Soaker hoses are connected to 2 of the barrels to distribute water along my house’s foundation.

Then I bought some  drip irrigation supplies recently with the intent to use the 3rd barrel to water my vegetable garden. However, through further investigation, I discovered that not all roofs are the same and I had to change my plans.

What’s On Your Roof

Some roofing materials contain chemicals that kill plants (and could make you sick too if you eat the plants). If your roofing contains questionable materials, use the water runoff only for landscaping and not for vegetables or herbs.

Although most newer composite roofs no longer use asbestos, many asphalt shingles have zinc particles embedded in their surfaces, and these types of roofs can leach complex hydrocarbon compounds. Although zinc has low-toxicity and there hasn’t been much testing on how much hydrocarbon compounds these roofs leak out, they are generally avoided for rainwater collection where the water is intended for vegetables and herbs.

Avoid using water from copper roofs or gutters because the acidity of rainwater can eventually cause copper leaching.

Some roofs have galvanized metal strips mounted at the roof peak that are used to discourage moss and mold. These can also add toxicity to water runoff.
Also, wood shingles, which fortunately are not common here in the Dallas area, are often treated with chromated copper arsenate (CCA) to make them resistant to rot, moss, algae, etc.

Finally, watch out for lead. Lead is sometimes used in flashing and in gutter solder.

A Simpler Approach

I’ve decided for the time being to take a simple approach and use the 3^rd barrel to water a decorative bed that is in the front of my yard, which will also enable be to reduce the amount of water that my sprinkler system currently delivers there. Then, I’m going to use city water on my vegetables.

Because the spigot for the tap water is further from my garden, I’m going to run a hose from the spigot to the edge of my garden and have it feed the drip irrigation system. However, this hose will be a marine/camper hose and not a regular garden hose, as almost all garden hoses contains lead in them. See The Lead In Your Garden Hose.    

A Slightly More Complex Approach

With more time and resources however, there are other ways to get rainwater from one’s roof. For example, enameled steel and glazed tile roofs generate little or no contamination, and you can use their rainwater run-off to water vegetables.

Some of the most suitable roofing materials for collecting potable water are:

• Colorbond steel sheets or tiles
• Zincalume steel sheets or tiles
• Glazed tiles that are well fired
• Concrete/cement tiles
• Clay tiles
• Fibro – newer type
• Composite tiles – bitumen based

One rainwater harvesting site offers some caution on cement and clay tiles however: “Cement and clay tile roofs can create some difficulties when it comes to collecting potable water. There are a lot of various minerals in the clay and cement used for making tiles and there is no guarantee the clay pit was not contaminated. The temperature tiles are usually fired at is not sufficient to fuse all minerals together to prevent them from leeching, thus it could never be guaranteed that a cement or clay tile roof would be as safe as some other types of roofing material.”

Also, there is an example where someone used rainwater harvesting with a composite roof, but added a FloTrue Smart Valve to divert the first 10-60 gallons of water during  rainfall (braewater.com) and then used a Katydyn Gravydyn 2 ½” gallon drip ceramic and carbon filter from REI.com. He claims that when he sent the water to a Ft. Worth testing company, it came back with:

• Lead .02 mg/liter
• Sulfates 1.3 mg/liter
• Nitrates - .02 mg/liter
• Fecal coliform – 0% none

So anything is possible. If you have successful rainwater harvesting examples, please post them here at The Dallas Green Zine.

References

Texas Manual on Rainwater Harvesting

Health Issues Involving Roofing Materials

More on Roof Comparisons
 
 

Senate bill 3335 was defeated in July for the 8th time.

This bill would have extended the investment tax credits for installing solar energy and the production tax credits for building wind turbines and other energy-efficiency systems.

This was a very important bill because Dallas is not Austin, and the lack of incentives here makes the installation of solar and wind technology very cost-prohibitive. And there is no support at the state level for anything ‘green’ (unless you consider that money is green).

Therefore, having a bill such as S. 3335 passed at the federal level would have not only helped many Texas residents but it would have offered a huge boost to the many businesses that are trying to get into an emerging green market.

Interestingly, this bill has been up to vote 8 times. Thomas L. Friedman writes in his New York Times Op-Ed, ‘Eight Strikes and You’re Out,’ that Obama has voted favorably 3 times to extend the credits and McCain has not shown up for any of the votes (and once, McCain was even in the Senate building at the time!). The fact that neither candidate showed up to vote on this bill is inexcusable, because a ‘no show’ carries similar weight as a “No’ vote. Getting elected may be the candidates’ primary concern right now, but no amount of campaign speeches on ‘the need for alternative energy’ can account for actions not taken. 

A more detailed description of the bill is provided here:
http://finance.senate.gov/sitepages/leg/leg072408S.3335.pdf

Thomas L. Friedman’s ‘Eight Strikes and You’re Out.’ New York Times, August 13, 2008. 
http://www.nytimes.com/2008/08/13/opinion/13friedman.html
 

Despite the stories that come out this time of year of pets (and children!) being found dead in cars, it seems that some people still don’t get it.

Don’t leave your pet or child in a heated car when the temperature is in the 60s or higher, even if the windows are open. If the outside temperature is 79 F, the temperature can climb to 90 degrees in the car in the shade or 140 F in the sun. Even being in the car for more than 5 minutes can be too long.

Also, leaving the air conditioning on is no guarantee… Last year a TX police officer left his dog in the car with the air conditioning running. The air conditioner stopped running,  and the dog was found dead.

Animals are at high risk from heat because they are do not sweat like we do. Dogs can only cool themselves by panting and by sweating through their paws. If they have only overheated air to breathe, they can collapse, and suffer brain damage and possibly die of heatstroke.

Keep this in mind as you’re taking your dog on trips. Always bring water for them. Plus, jogging through the park might be fine for you but it might be too much for your dog.

And one heat-related note from paw-rescue.org:

“Don’t let dogs ride loose in pick-up truck beds. The hot metal can burn a dog’s paws, the sun and flying debris can hurt the dog, the dog can accidentally be thrown out of the truck if the brakes are suddenly applied, and the dog can jump out if scared or upon seeing something interesting to chase.”

Recent surveys of home buyers and builders have found that buyers are willing to pay more for energy efficiency.

Seventy-five percent of homeowners in a new homes survey said that energy-efficient features would most influence their decision to purchase a home.

The top 3 in ‘must have’ features:

• a high level of insulation 
• Energy Star-rated windows
• energy-saving equipment

In another survey of 250 U.S. residential builders, builders said that buyers are willing to pay 11-25% for green built homes.

And if you think that the trend is coming from retiring baby boomers, looking for smaller and more energy efficient homes, think again… The average green homebuyer is:

• between 35-50 years old
• has a college degree
• has a fair understanding of green products

When builders were asked why they don’t use more green products, they cited that price and availability are the key constraints.

Taken from:

NAHB and Better Homes and Gardens Survey

Green Builder Media and Imre Communications (January 2007)