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
 
 

You can get good quality mulch for free at the Garland recycling center.

It is open 8:00 a.m. - 5:00 p.m. Monday - Friday, and 8:00 a.m. - 3:00 p.m. Saturday. Click here for a map of its location at 1426 Commerce Street, Garland, TX 75040:

The mulch is in a large, long rectangular bin that has 3-4 foot high sides, and is open on one end.

The best way to get mulch is to park a pickup truck up next to the bin, stand on the top of the mulch pile in the bin, and use a pitchfork to shovel the mulch into the bed of the truck.

We don’t have a truck, so we took lots of garbage bags and filled them up with mulch.  You can shovel the mulch into garbage bags.  We found it easier to use a metal rake to loosen the mulch and use our hands to scoop it into garbage bags.

We put mulch around our trees, bushes, and house foundation to reduce the soil temperature and keep the soil moist.

Many of us use hoses to water our gardens, fill our dogs’ water bowls, and fill pools. I’m sure that kids still drink water from them occasionally too. So, I was surprised to learn the other day that many hoses are made of polyvinyl chloride, which uses lead as a stabilizer.

I wouldn’t have known about this if I hadn’t seen the small tag attached to a hose I picked up at the local big box DIY store that read, This product contains a chemical known to the State of California to cause cancer and birth defects and other reproductive harm. Interestingly, this tag was not on the other groups of hoses, which had no markings on them whatsoever. Instead of just buying an unlabeled ‘mystery’ hose, I looked online and found a Consumer Reports study showing that of the 16 hoses they tested:

• 4 were labeled safe for drinking
• 6 had warning labels
• 6 weren’t labeled

All of the hoses leached some lead but the ’safe’ hoses leached no more lead than would be found in drinking water. Two hoses leached 10 to 100 times the allowable lead levels.

 

So, when you buy a hose, choose one labeled safe for drinking. And with any hose, flush it by letting the water run for a minute or so before you drink.

Buying organic produce is one way of avoiding foods with pesticides or genetic modifications. 

After all, some pestcides cannot be washed off and others are designed to bind to the surface of the produce and don’t wash off easily.

But ‘organic’ is expensive. If you can afford to buy organic only some of the time, consider going organic with those foods which have the highest pesticide contamination.

Here are the top 15 fruits and veggies having the highest pesticide load (with peaches being the worst).

1 peaches
2 apples
3 sweet bell peppers
4 celery
5 nectarines
6 strawberries
7 cherries
8 pears
9 grapes -imported
10 spinach
11 lettuce
12 potatoes
13 carrots
14 green beans
15 hot peppers

For the complete list of 43 fruits and vegetables ranked based on pesticides, visit Food News.

The lowest in pesticides are:

asparagus
avocados
bananas
broccoli
cauliflower
corn (sweet)
kiwi
mangoes
onions
papaya
pineapples
peas (sweet)
 

Longing for a garden? But perhaps you live in an apartment or your yard is too small? Consider participating in one of these community gardens:

• Community Harvest (Plano)
• Coppell Community Gardens (Coppell)

…or start a community garden! 

Community Harvest is a community garden in Plano where you can have your own 16′ x 4′ plot to grow fresh vegetables and more on large raised beds, using organic techniques. Ten percent of the food is donated to local food pantries.

The program started last February and 19 plots are already in use. If you’re interested in getting a plot for the 2008 growing season, call Community Harvest at 972-424-8989 and leave a message. This is a great opportunity to grow your own food, meet other gardeners and neighbors, learn from epxerienced gardeners, and contribute to local food pantries. Each lot costs $35 for the year. The Community Harvest garden, which is sponsored by the Community Unitarian Universalist Church, is located at 2875 E. Parker Road in Plano.

The Coppell Community Garden offers similar opportunities through Helping Hands Garden (at 255 Parkway Blvd.) and Ground Delivery Garden (at 450 Denton Tap. These two gardens have a total of 100 plots. Since the program started in 1998, over 27,000 pounds of fresh produce grown by volunteer gardens has been donated to families in need.

For more information about the Coppell gardens, contact kcb@ci.coppell.tx.us or 972-462-5191. There is also a website here.

Consider starting a community garden in your area. Identify those who have already started community gardens and ask them how they got started. Also, for more information, check out these links:

• American Community Gardening Association 
• Tips on Starting a Community Garden
• Resource Guide for Starting a Community Garden
• Starting a Community Garden