Collecting, Filtering, And Reusing Rainwater Is An Expensive Concept And Lengthy Process, But Can Benefit A Facility With A Reasonable Return On Investment.




In metropolitan areas, especially those with combined sanitary and storm sewers, it is often a requirement that a new building must include a system for storm water detention. This is a system that collects the rainwater and stores it so that it may be released at a rate slow enough that the flow can be safely assimilated by the existing sewer system. Unfortunately, and ironically, many of these jurisdictions that require rainwater capture and detention do not allow for it to actually be used.

Combined sewer overflows demographics

Combined sewer systems are remnants of the country's early infrastructure and so are typically found in older communities. Combined sewer systems serve roughly 772 communities containing about 40 million people. Most communities with combined sewer systems are located in the Northeast, the Great Lakes regions, and the Pacific Northwest.



Rainwater harvesting is most often referred to as an “emerging technology”; however, rainwater cisterns are not a new concept. In the Middle East in 2000 B.C., typical middle-class dwellings stored rainwater in cisterns for use as a domestic supply as well as private bathing facilities for the wealthy. The reason that the construction of this type of large public underground cistern may have been abandoned as a rainwater harvesting system strategy could be due to the fact that the construction of underground cisterns is considerably more expensive than the construction of dams and some other alternatives. Our failure to appreciate the value of rainwater, coupled with the perception of construction costs, has rendered rainwater harvesting somewhat of a lost art.



System design professionals

Alternative water source systems (AWSS) should always be designed and sized by design professionals possessing either a Certified in Plumbing Design (CPD) certification from the American Society of Plumbing Engineers (ASPE) or a Professional Engineer (PE) license, and certification from theAmerican Rainwater Catchment Society of America (ARCSA) as an ARCSA Accredited Professional (ARCSA-AP).



1. Collection

The first part of the system that the rain comes into contact with is the roof itself. Although the plumbing engineer does not usually design the roof, he or she is often consulted or at least has an opportunity to contribute some input. The roof is a critical component of the rainwater harvesting system and will define some of the other system components such as filtration. Recommended roofing materials include standing seam metal, ethylene propylene diene monomer (EDPM), and slate or tile.



The following roofing materials are not recommended for rainwater harvesting:

• Asphalt: One of the most common roofing materials used in the U.S. is asphalt. Unfortunately, this is not a good surface from which to harvest rain that is intended for potable use. Crumbling asphalt roofing material debris can be separated during filtration, but this type of shingle can also leach petroleum products into the water. These contaminants can also be removed from the captured rainwater, but it is preferable to keep them from entering our system in the first place.
• Wooden shingles: Wooden shingles are porous and can be a fertile medium for the growth of mold and fungi that will be introduced into our rainwater harvesting system. They are also treated with chemicals that are intended to protect the wood, but are neither intended nor acceptable for human consumption.
• Unprotected metal: There have been cases of unacceptable levels of heavy metal contaminants in vegetables that were irrigated from rainwater harvested from metal roofing materials. Tests have indicated that these bare metal roofs can contribute to heavy metal levels that exceed the allowable limits. If this water is used to irrigate non-edible vegetation, then it might be acceptable. However, as there could still be a risk of contamination, unprotected metal should not be included in a rainwater harvesting system. Note that some modern metal roofing materials may be exempt from these comments, especially if they include protective coatings.

The following roofing materials are recommended for rainwater harvesting:

• Standing seam metal: Standing seam metal roofs can be an excellent material for rainwater harvesting. A standing seam roof is constructed of many interlocking panels that run vertically from the roof's ridge to the eave. The interlocking seam where two panels join together is raised above the roof's flat surface, allowing water to run off without seeping between panels.
• EPDM: Ethylene propylene diene monomer (EPDM) is a rubber-like compound that has been used in roofs in the U.S. since the 1960s and is one of the most common types of low-slope roofing materials. This is because it is relatively inexpensive, simple to install, and fairly clean to work with when compared to conventional built-up roofs.
• Slate or tile: Slate is a good surface to harvest rain from as long as it is kept clean. One possible advantage of slate and tile is that they do not deteriorate. These materials do not include asbestos tiles, which have been mainly used as siding in the past but could potentially be found on some roof surfaces.

2. Storage

Storage tanks come in many shapes, sizes, and materials. They can be located below grade, above grade, near the roof, or in many other locations.

The appropriate tank size depends on:

• Roof collection area
• Anticipated local rainfall, and
• Our intended use of the collected water.

There could be some benefits to sizing the tanks so that they overflow regularly to provide skimming of the water surface, but large enough to provide a reliable water supply. The storage tanks are typically the largest expense in a rainwater harvesting system. This makes it critical for calculating the return on investment (ROI) or payback time.



3. Filtration and disinfection

There are many facets of this process to consider. We will generally need several types of filtration and disinfection components to produce a suitable quality of water. The quality of water may be subject to our intended use of it, but generally we will be required by the authorities to deliver water of potable standards, even though they usually will not allow it to be used as potable water.



First flush, roof washers, or rain diverters flush off the first water of a storm before it enters the storage tank. This water most likely would be contaminated by particulates, bird droppings, and other materials on the roof surface. We can improve the quality of collected water and increase the efficiency of our filtration/disinfection systems by diverting this first flush of water to the storm sewer rather introducing it into our collection system. This could be accomplished with a manufactured device or a diverter pipe of sufficient liquid holding capacity, or with some type of constructed basin with overflows. The manufactured devices usually are touted as “self-cleaning” but still require access for occasional inspection and maintenance.

General rules of thumb:

• First flush devices should remove about 10 gallons of water per 1,000 sq ft of roof/catchment area.
• Remember to size for each downspout of the catchment/roof area.
• If harvesting rainwater in an area with lots of dust or other pollution sources, a larger first flush device is recommended.
• First flush devices must be easy to open and maintain. If not, the device will most likely be disabled.

  

4. Delivery

One of officials’ biggest concerns is the potential for cross-connections with potable water supply. Private and municipal potable water systems must be protected from this contamination, and such protection may be provided by physical air gaps, break tanks, or reduced-pressure-type vacuum breakers (RPZ), as required/approved by the local authority having jurisdiction (AHJ).

Pipe identification also requires some consideration. There is still a lack of industry-wide agreement on how to label the piping and what color it should be. Piping manufacturers are producing pre-labeled piping in purple plastic, but it is still not an agreed-upon standard for all jurisdictions. From many AHJs’ perspectives, there are only two types of water: potable and nonpotable. Implementing the use of purple pipe for all nonpotable water is intended to prevent cross-connection between the two. In addition, gas industry engineers are concerned that a yellow alternate water pipe could be confused with a natural gas pipe, which is also yellow.

That being said, it seems that the general consensus is that piping that carries water from any AWSS shall be purple in color and labeled every 5 ft as to its contents. The label should note that the nonpotable water is not for consumption, unless the system is approved by local authorities to be used for potable purposes.

The type of pumping system that we include in our system will depend on other design components. One of the most popular systems provides submersible pumps within the stage tank system. These pumps should always include floating inlets with integral strainers. These inlets float below the surface of the water so that they are presumably capturing the cleanest of the stored water. The inlets lie below potential contaminants that are floating on the surface, and above any sediment that might have accumulated on the bottom of the tank.



Sizing rainwater systems

Historical rainfall data is needed in order to be able to base the system design. The rainfall rate, or intensity, is a term that relates the quantity of rainfall to a unit of time.

The rainfall rate used for designing roof drainage systems is related to the average frequency of occurrence and the time that it takes runoff to reach the collection device from the most remote portion of the contributing roof area. The average frequency of occurrence, also referred to as the return period, is an indication of the average number of years between storms that will produce rainfall rates equaling or exceeding a given amount. The amount of time that it takes the runoff to reach the collection device from the most remote portion of the tributary area is known as the time of concentration.

The duration of a storm equals the time of concentration and is the period of time during which the heaviest rainfall occurs and, in theory, when the greatest amount of runoff occurs. The rainfall rate used for the design of roof drainage systems is based on a 10-year return period and 5-minute duration. The 10-year, 5-minute rainfall rate is recommended as a minimum for use in designing roof drainage systems. Historically, it has been relatively accurate.

An example of a simplified method of cistern sizing is a 15,000-sq-ft roof in Minnesota, during the month of July, with a 4.34-in monthly rainfall. Since each square-foot of roof surface can generate approximately 0.62 gal of usable water per inch of rainfall, this particular roof could generate 40,362 gal of water.

In this case, a 40,000-gal cistern may not be practical, but cisterns generally should be as big as the project can afford in terms of both expense and space. They are the biggest and generally the most expensive part of the system.



Detailed cistern sizing method:

1. Obtain monthly rainfall averages for a given location.
2. Determine the catchment footprint area.
3. Determine the runoff coefficient from tables published by ASPE and ARCSA.
4. Determine the safety factor based on knowledge of the site and discussion.
5. Obtain the monthly catchment potential by multiplying the column entries on each row.
6. Calculate the annual catchment amount by multiplying the total annual rainfall rates in the last row of columns B, C, D, and E.
7. Double-check the results by comparing the annual catchment to the sum of each month found.
8. Review the monthly supply amount in column F.
   1. Identify highs and lows
   2. Observe patterns in data
   3. Identify the highest 4 months
   4. Identify the lowest 4 months 
   5. Identify the months where capture potential is zero.

For outdoor irrigation use, rainwater requirements will vary based on:

• The climate of the location
• The types of plants
• Amount of exposure to direct summer sun
• Soil conditions
• Presence or lack of mulch
• Size of the area irrigated.

All of these factors will determine how much irrigation water is needed. Large landscapes with large water demands may not be readily accommodated by rainwater catchment systems.

Determine site water requirements with the following equation:  



Where:

Q = Flow in GPM

A = Area in square feet

WR = Water Requirement in inches per week

0.6234 = volume of water in 1 sq ft 1-in. deep

D = Number of days per week available for irrigation

H = Hours per day

DU = Distribution Uniformity or System Efficiency

*Consider that the WR = Water Requirement should be roughly equivalent Q + 25%.

Rainwater harvesting system cost

The cost of a rainwater harvesting system depends on the size of the system. A simple system for a commercial building could be as little as $10,000, while a complete system for a commercial building could be $100,000 or higher.

Developing a budget for a rainwater harvesting system may be as simple as adding up the prices for each of the components and deciding how that coincides with the budget expectations. The largest expense is the storage tank, and the cost of the tank is based upon the size and the material. Costs can range from as low as about $0.50 per gallon for large fiberglass tanks to up to $4.00 per gallon for welded steel tanks. As tank sizes increase, unit costs per gallon of storage decrease. There is also an installation cost, which can also vary greatly. An underground tank will cost much more for excavation and anchoring. An improperly anchored underground tank can "float" out of the ground and cause damage even if it only moves a little. System providers as well as Means Cost Data should be consulted when preparing cost estimates.

Operating costs

Operating costs should be considered as you prepare your budget. As with any water treatment system, the cleaner the water needs to be, the greater the efforts required to maintain the system. Fortunately, with filter cartridges, this just means regular replacement of the cartridges, and with the disinfection system, following the manufacturers’ recommendations for regular maintenance. But proper operation and maintenance of the system does add to total costs.

Filter cartridges should be replaced per the manufacturer’s specifications, based upon the rate of water use. Some of the operating costs and time expenditures necessary for system maintenance are regularly cleaning gutters and roof washers, checking the system for leaks by monitoring water levels, and paying close attention to water use rates to determine if an invisible leak has sprung. Although the “do-it-yourselfers” can handle all of these tasks with little added financial burden, the time for regular maintenance and operation must be set aside to operate a successful system.

Comparing to other sources of water

In some areas, the cost of drilling a well can be as high as $20,000 or more, with no guarantee of hitting a reliable source of water. The deeper the well, the more expensive the effort will be. Also, well water can have very high total dissolved solid (TDS) levels in some aquifers, resulting in “hard” water. Rainwater is naturally soft and has become a preferred option in some parts of the country with costs lower than or equal to those of drilling a well, and reliability high enough to justify reliance on weather patterns, rather than on an aquifer’s water quality and quantity.

ROI and financial budget calculations

In terms of financial considerations, rainwater budget calculations can be used for a basis of water savings, but cost data, such as the costs of water and sewage, is needed to evaluate the system further. Sewer charges are normally based on the water meter readings.



Plumbing codes and treatment

In the U.S., we routinely design buildings that use clean drinking water for flushing toilets and for landscape irrigation. Only about 1% of municipally distributed potable water is used for purposes that actually require potable water: drinking, cooking, and bathing. Green building practices are becoming more desirable and prevalent, and more emphasis is being placed on water conservation in building design. The U.S. Green Building Council’s LEED 2009: Technical advancements to the LEED rating system is one example of a demonstration of growing appreciation for this vital resource, as water credits have increased significantly from previous versions of LEED Certification requirements. Some of the more common water-conserving strategies that are being implemented include specification of low-flow toilet fixtures including dual-flush toilets, sensor-operated lavatories, and waterless urinals. Other measures include the use of gray water, reclaimed water, and rainwater harvesting (rainwater catchment). Stored rainwater collected from a large catchment surface is a cost-effective source of water for landscape irrigation and toilet flushing. The use of rainwater as a domestic-water source not only decreases the amount of clean drinking water used by a building, but it also decreases the amount of storm water runoff from the site, which in turn lessens its effect on erosion and decreases the load on storm sewers and waterways.

Authorities worldwide, including the Uniform Plumbing Code (UPC), the International Plumbing Code (IPC), ASHRAE, and others, are writing codes to address alternative water systems. While the national standards are currently behind in the realm of the design and installation of rainwater harvesting systems, some state and local authorities have issued codes, guidelines, and ordinances to address these systems. The IPC and UPC are both working to fully address the subject of rainwater harvesting and provide guidance to the design community on a national and international level.

Some states that already have in place, or under consideration, some form of regulations, guidelines, tax incentives, or assistance include:

• Alaska
• Arizona
• California
• Colorado
• Florida
• Georgia
• Hawaii
• Illinois
• New Mexico
• North Carolina
• Ohio
• Oregon
• Texas
• Utah
• Vermont
• Virginia
• Washington
• U.S. Virgin Islands

International

• Australia
• India
• United Kingdom

Alternate materials and methods

Almost all codes include sections that deal with alternate materials, methods, systems, and equipment. An alternative material or method of construction shall be approved where the code official finds that the proposed design is satisfactory and complies with the intent of the provisions of this code, and that the material, method, or work offered is, for the purpose intended, at least the equivalent of that prescribed in this code in quality, strength, effectiveness, fire resistance, durability and safety.

This provides the code official with the flexibility to approve the installation of a rainwater harvesting system even if that system is not specifically addressed by the pertinent code. The design engineer must submit an application known as an Alternate Materials and Methods Request (AMMR), available from the building department. Approval is subject to review on a case-by-case basis. In some jurisdictions, separate approvals may be needed for state and local authorities. Alternatively, some jurisdictions will actually require rainwater capture and detention, and some even require rainwater to be reused on-site.

Usually, a licensed professional engineer is responsible for the proper operation of the system. Some states and codes acknowledge the CPD (formerly CIPE) designation that is certified by ASPE. The most important consideration is that if an alternative system is contemplated, it must be submitted to and approved by the AHJs. To expedite approval, the following checklist may be helpful.

 



Additional strategies

Enlist help. Seek out knowledgeable experts and resource people, including sympathetic code officials, to support your position.

Show respect for their position. Consider the building department a resource rather than an adversary. Maintain a cooperative, open-minded, and positive attitude, acknowledging that the building officials have the authority to approve alternatives that meet the intent of the code.

Develop relationships. Nurture trust, both in your design approach and in your willingness to meet the intent of the code. Having a good relationship with the building department is essential.

Meet and share information with building officials. Arrange an initial meeting to formally discuss the project and proposed alternatives.

Network. Cultivate relationships with experienced building officials who have approved and worked with the materials or methods in question, or who are open-minded and receptive to alternatives.

Ultimately, the AHJ has the last word. The local and state authorities have an obligation to ensure that the public water supply is safe and secure, in both quality and quantity.

Going forward

To learn more about these systems, consult ASPE and ARCSA publications. Both organizations also provide technical seminars and training opportunities on these subjects, and are involved with the writing of standards to define these practices and systems.

David E. DeBord CPD, LEED AP BD+C, ARCSA AP, has over 30 years in the consulting business. David is employed as a Plumbing Engineer at Environmental Systems Design in Chicago. He is a Senior Associate and serves as the TA (Technical Authority) in the International-Special Projects Group. David is the Legislative Vice President of ASPE (American Society of Plumbing Engineers) at the Society level and an Adjunct Assistant Professor at Illinois Institute of Technology. He is member and a Past President of the Chicago Chapter of ASPE. He is also a member of the American Rainwater Catchment Society of America (ARCSA), American Solar Energy Society (ASES), the Geothermal Heat Pump Consortium (GHPC), USGBC, and serves on code committees of the ICC and IAPMO. He has been published in several publications and writes data book chapters for ASPE. He also presents webinars and lectures for ASPE and other organizations.

References and additional information

Refer to publications from ASPE (American Society of Plumbing Engineers) and ARCSA (American Rainwater Catchment Systems Association), including the jointly published Rainwater Catchment Design and Installation Standards publication, as well as the IGCC (International Green Construction code), the Green Supplement from IAPMO, and various publications of the Texas Water Development Board. Some of the information above references these materials. The websites of the EPA andNational Oceanic and Atmospheric Administration (NOAA) also have a large amount of relative information.

Pretoria - Rainwater harvesting should be made compulsory in all urban areas, the Agriculture Research Council said on Monday.

"The majority of people are not doing enough [to combat climate change]," said CEO Shadrack Moephuli.

"People are still using tap water for their lawns and swimming pools. But they don't cover their pools to prevent evaporation."

Moephuli spoke in Pretoria at the Consultative Group on International Agricultural Research's conference on water and food.

He said if urban dwellers were forced to harvest and store the rain water from their roofs, it would reduce pressure on the country's water resources.

"It takes very little effort to harvest water," he said.

He also advocated stiffer penalties for the water wastage.

Delegates to the conference, which ends on Thursday, heard the Limpopo River basin was expected to face diminished rainfall and higher temperatures as a result of climate change.

The basin is home to some 14 million people in South Africa, Botswana, Zimbabwe and Mozambique.

Moephuli said re-using partially treated waste water for agricultural purposes should be considered.

There needed to be a long-term strategy to manage the regions water resources and ensure it was not wasted.

He said a greater effort was needed by local authorities to ensure that leaking plumbing did not contribute to the loss of water.



- SAPA

Precast concrete infrastructural products and solutions provider Rocla Southern Africa, in collaboration with Rocla Australia, has launched the Rocla ecoRain and the ecoRain with water harvesting systems in a bid to encour- age rainwater harvesting, retention and reuse.

“South Africa is one of the many countries today faced with water problems, including the high cost of potable water to consumers. In Australia, there has been a shift towards water sustainable cities and integrated water cycle management. These systems aim to conserve potable supply by implementing the rain- water capture and reuse aspects of water-sensitive urban design,” says Rocla sales engineer Justin Kretzmar.

Authorities and research organisations in Australia have established that, by using rainwater tanks for nonpotable applications, the need for expensive systems, such as desalin- ation and recycled wastewater, can be delayed. In leveraging this, many developers and municipalities are changing legislation and building codes to require the installation of rainwater tanks for toilet flushing, irrigation and laundry uses.

“With South Africa facing sanitation and water challenges, the ecoRain systems, which are designed to capture clean rainwater that is then stored underground for further use, could be provide a solution. As the source and quality of any captured water cannot be assured, the ecoRain system is intended to deliver stored rainwater for nonpotable applications, thereby saving costs and dealing with some of the sanitation challenges, while conserving potable water.

“The captured water is conveyed through numerous roof gutter downpipes to the ecoRain filter, which removes all debris and waste greater than 0.5 mm in diameter in particle size. Only clean water is then transferred to the ecoRain concrete tank, while the coarse litter is continuously removed from the filter and discharged through the overflow to the stormwater drainage system,” explains Kretzmar.

The Rocla concrete tank is strong and durable, with a long life span. As the tank is installed underground, it will not take up valuable land space and the load-bearing capacity allows it to be located almost anywhere on site.

“Underground concrete tanks are an ideal method for storing water, proving to be an almost germ-free environment away from light and heat. Concrete cisterns are strong and durable, and last indefinitely and help to neutralise rainwater,” says Kretzmar.

The sustainability of scarce resources is a global imperative and, with Rocla concrete tanks, the capability of existing water supply systems will extend to keep pace with population growth. Harvested water can be used for flushing toilets, laundry, car washing and irrigation, besides other applications.

Common rainwater harvesting systems are made of plastic and are traditionally placed above ground, exposing the tank to heat and sunlight, which are detrimental to the quality of water.

For the past few years, one of the most common questions facing the Texas Water Development Board (TWDB) hasn’t been over contentious water rights or proposed water projects; it’s been from homeowners wanting to know what type of roofing material is most suitable for collecting rainwater for indoor domestic use.

“Rainwater harvesting is becoming fairly widespread, at least in Central Texas. There’s interest born out of necessity because people are simply running out of water in rural areas or they’re interested in conserving water supplies and it’s good for the environment,” said Dr. Sanjeev Kalaswad, the TWDB’s  rainwater harvesting coordinator.

But when it came to responding to residents’ questions about which roof collection surfaces are best suited for rainwater harvesting, TWDB didn’t have a good, science-based answer to give, Kalaswad said. That’s when the Cockrell School of Engineering came in to help.

With funding from TWDB, Cockrell School faculty and students conducted an in-depth study - recently published in the academic journal Water Research -examining the effects of conventional and alternative roofing materials on the quality of harvested rainwater. The study, led by civil, architectural and environmental engineering Assistant Professor Mary Jo Kirisits, showed that, of the five roofing materials tested, metal (specifically Galvalume®), concrete tile and cool roofs produce the highest harvested rainwater quality for indoor domestic use. The study also showed that rainwater from asphalt fiberglass shingle roofs and increasingly popular “green” roofs contain high levels of dissolved organic carbon (DOC). Although other potential pollutants can be significantly lower on green roofs (turbidity and aluminum), the high DOCs are significant where these roofs would be used for potable rainwater collection.

Water with DOC is not necessarily dangerous on its own, but Kirisits said when it’s mixed with chlorine – a common product used to disinfect water – the two substances react to form byproducts that potentially cause cancer and other negative human health effects.

“Someone who already has a rainwater system is probably not going to change their roofing material based on this study, but this information is useful for anyone who’s trying to make an informed decision about what material to use,” Kirisits said.

Over the course of a year, Kirisits, her co-Principal Investigators Professor Kerry Kinney and Research Associate Professor Michael Barrett and their engineering students examined water collected from five roofing materials: asphalt fiberglass shingle, Galvalume®, concrete tile, cool and green roofs.

The test sites included both pilot-scale and full-scale residential roofs — one of which was the roof on the home of Kirisits and her husband. The other roofs were located at or near the Lady Bird Johnson Wildflower Center, where her team had the expertise of the center’s director of research and consulting, Dr. Mark Simmons, who helped them interpret some of their findings.

“We had a phenomenal graduate and undergraduate student team. I think the research topic captured their imagination because it’s tangible; it’s something they could do in their own home. They can talk to their parents about it and they get it,” Kirisits said. “Our generation of students is sustainable and green-minded, so it was a great project for them to be involved in and lead.”

Rainwater harvesting has been practiced in some form or another for centuries, but its popularity declined in the United States after the advent of large centralized water supply systems that provide cheap, reliable and abundant water.

The practice has experienced a rebirth in the United States in recent years, however, thanks largely to growing environmental concerns and dwindling water supplies in parts of the country.

The U.S. Environmental Protection Agency doesn’t regulate the quality of residential rainwater collected through harvesting, but some local agencies and states, like Texas and Hawaii — which are among the most proactive –  offer voluntary water quality guidelines.

While some roofing materials performed better than others in the study, Kirisits said rainwater harvested from each of the roofs would still have to be treated if the consumer wanted to meet EPA’s drinking water standards or reuse guidelines.

The complete study by Kirisits and her students is available on TWDB’s Web site.

Going green with gray waterby Larry Copenhaver on Jul. 19, 2006, under Local
Recycling a legal way to cut addiction to the garden hose

An outdoor shower lets gray-water advocate Brad Lancaster get clean and water his midtown front yard.

A blistering, long-term drought.

Water rates going up in August.

A lazy summer monsoon.

Sounds dismal for thirsty plants in southern Arizona, but there is a “brand-new” source of irrigation water and it’s already in your home.

It’s called gray water, which is water used in a shower, washer or lavatory, says Val L. Little, director of the University of Arizona’s Water Conservation Alliance of Southern Arizona, better known as the Water CASA.

Few people seem to realize that since January 2001, using gray water is legal for most irrigation, Little said. With a few alterations to a plumbing system, many homeowners can virtually get off the hose.

There are huge benefits to using gray water, even beyond the potential water savings.

Water dumped down the drain often requires electricity to pump it to a sewage treatment plant. Then a lot of energy is used to process it there.

Then more energy is required to pump the byproducts into the Santa Cruz River.

The average person creates an estimated 20 to 35 gallons of gray water per day, Little said. With about a million people living in Pima County, that means a potential 20 million to 35 million gallons of gray water is wasted every day.

An estimated 16 million gallons of gray water is produced by customers of Tucson Water, said the utility’s spokesman, Mitch Basefsky.

The gray water starts out in our homes as clean, potable water. So far this year Tucson Water customers used an average of 124 million gallons of potable water every day.

The record high consumption by Tucson Water customers this year was 49 million gallons on June 19. The all-time record for Tucson Water was 165 million gallons on July 14, 2005.

The average consumption for a winter day, when irrigation is at a minimum, is 75 million gallons.

“That leaves a lot of potential of gray water that could be used for most irrigation,” he said. “That’s why we are looking at incentives for new construction, such as discounts on building permits, to have plumbing installed to make it easier to use gray water.”

And the sooner the better, added Brad Lancaster, a gray-water use advocate and author of a book on ways to cut down on using potable water for irrigation.

To save energy, the UA graduate recommends that gravity be the only source of power, and he advises against storage tanks and pumps.

Contour your yard with depressions and berms so that water pools, and when a pool is full, the water overflows to the next depression, he said.

From a financial perspective, using gray water instead of potable water could save a family about $1.60 per month for each family member.

While saving money is not the main reason for conserving natural resources, it is an issue, Basefsky said. Tucson Water will raise rates Aug. 7 by an average of 4.6 percent, or about $1.06 per customer per month.

“But it’s one thing to say, ‘Let’s use gray water instead of pure water,’ but you’d have to replumb all those houses,” he noted. That can be easy in some homes, but virtually impossible in others.

Water CASA estimates the cost of retrofitting a home at $135 to $1,250 plus installation.

The best time to plumb a home for harvesting gray water is during its construction, said Brad DeSpain, utilities director for Marana. That’s why Marana plans in its building code to require gray water systems be mandatory in new construction.

“We are working very hard to get that accomplished, possibly to go into effect next July 1,” DeSpain said. “I don’t see any big resistance, and the town management favors it.”

He said such a change would slightly increase the cost of the home, varying according to its size and design.

DeSpain said he did not wait for the town to require using gray water. He has retrofitted his home with a system that routes gray water for irrigation.

Lancaster said he combines his gray water with water harvesting – collecting rainwater from his roof. Using both allows him to wean his trees off potable water in all but the driest of seasons.

“I advocate the creation of an oasis zone around the house, up to about 30 feet from the outside walls,” he said.

It’s especially important to provide shade on the east and west sides of the home, he said. That can reduce the ambient air temperature near the home in the summer by as much as 20 degrees.

“This becomes a dynamic passive cooling strategy so they can greatly reduce or even eliminate mechanical cooling which otherwise consumes a great deal of energy at the power station and with the air conditioners.”

Some of those trees should be fruit or nut trees that provide fresh food, he said. “On-site food production is another way to reduce energy consumption.”

Most food is trucked into Tucson and that requires energy through the consumption of fossil fuels.

“So here you are, not pumping that water, and you are not transporting that food,” Lancaster said. “You are getting healthier food because it’s fresher and you can produce it organically onsite with rainwater and gray water.”

And by using the passive basins and berms, people are not given another chore to add to their already busy schedule, Lancaster said. When the rain comes or the gray water flows, there is no other action required by homeowners.

Actually, saving water is a lot of fun, said Lancaster who installed a shower that uses solar-heated water in his side yard. “I’m jazzed about it. I know the gray water is going to irrigate my trees which cools my house and provides me with food.”

Brad Lancaster, author of a book on ways to cut down on using potable water for irrigation, recommends against storing water in tanks.

——--

BY THE NUMBERS

20-35: Gallons of gray water the average person produces a day

$135-$1,250: Cost of retrofitting and installing a gray water system

124 million: Gallons of Tucson Water customers use on an average day

——--

WHAT IS GRAY WATER?

● Gray water is wastewater from the laundry, baths, showers and lavatories

● Water from kitchen sinks and toilets in considered “black water,” which is not suitable for home irrigation.

● Laundry water from washing diapers is considered black water.

● Water from kitchen sinks and dishwashers contains food debris and grease. It is considered black water.

WHERE WATER GOES

● Homes with in-ground sprinkler systems use 35 percent more water than other homes.

● Homes with automatic timers to control their irrigation systems use 47 percent more water than other homes.

● Homes with drip irrigation use 16 percent more water than those without drip irrigation.

● Homes with gardens use 30 percent more water than those without gardens.

● Homes with access to another nonutility-water source have 25 percent lower outdoor use than those using only utility-supplied water.

Source: The Water Conservation Alliance of Southern Arizona

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CHECK LIST FOR RETROFITTING A HOME

● Direct gray water at least 4 feet away from a building foundation

● Consult a plumber if you are unsure of your own expertise.

● Get a free plumbing permit and inspection for gray water.

● If you use chlorine bleach or high-sodium detergents, plumb your system so you can dump those products into the sewer line.

● Clearly identify gray water plumbing from potable water lines.

● Make sure that tapping into your plumbing system does not damage or create problems with black water disposal.

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It’s raining barrels.

New York City is giving away 55-gallon rain barrels to homeowners to help conserve water and reduce pressure on the city’s sewer system, which is often overwhelmed during heavy storms. The city started promoting the barrels by distributing a few hundred of them in Queens in 2008 and 750 more in 2009 to homeowners who applied for them. This year, 1,000 free barrels are being distributed to owners of single- and two-family homes on a first-come-first-served basis at events in the Bronx, Brooklyn, Queens and Staten Island.

On average, the city’s Department of Environmental Protection said, as much as 40 percent of the water homeowners use goes to irrigate gardens and lawns during the summer.

The barrels, which connect to the downspout that takes water from the roof of a house and sell for about $150 at stores, are a simple way for people to save money on water bills while helping reduce the stress on the sewer system, which discharges a mix of storm water and untreated sewage into New York Harbor when it is overloaded during rainstorms, officials said.

“These rain barrels will capture thousands of gallons of water that would have otherwise flowed into the streets, leading to flooding and increasing the likelihood and intensity of combined sewer overflow,” said Cas Holloway, the city’s environmental protection commissioner.

The next barrel distributions are scheduled for:

• Queens: Saturday, 9 a.m. to 2 p.m., at Cunningham Park, 196th Place and Union Turnpike.
• The Bronx: May 7, 9 a.m. to 2 p.m., at Pelham Bay Park, in the Middletown Road parking lot on Stadium Avenue.
• Staten Island: May 7, 9 a.m. to 2 p.m., at the College of Staten Island, 2800 Victory Boulevard.

We are happy to be recognized by JoJo Water Tanks as a preferred installer of their products in Gauteng. This is due to the high quality of workmanship exhibited by our installation teams and our commitment to getting water harvesting installations right.

The pretty gardens, lush green lawns and exotic plants may all be a thing of the past for most homeowners as water experts warn not only that South Africa may run out of water in the next 10 years but that Eskom-style increases in water tariffs are on the way. Many cities and towns are unable to account for significant water losses. It also follows reports that the costs of municipal services have increased by 46% year on year. Water Affairs acting director-general Trevor Baltzer says that cheap water is a thing of the past and that government is looking at ways to fund new developments that will provide security of supply in the coming years. Indigent households will continue to receive free water from government but a new scale for water tariffs has will be submitted to the Cabinet for approval before the end of the year. Once approved, the new tariff structure will be released for general comment. The Trans-Caledon Tunnel Authority’s business analyst and water expert Richard Holden, claims that the water tariffs being charged by municipalities does not cover the actual costs of infrastructure maintenance and repairs. He says that a lack of funding would contribute to a collapsing infrastructure and could result in high losses and be detrimental to consumers. He has urged municipalities to start implementing higher water tariffs now so that, in the future, they can be spared sudden, massive and unexpected hikes in the costs of water. Water losses in South Africa are known to be excessive particularly in municipalities where pipes have not regularly been replaced as they rust. Moreover, burst pipes – which also contribute to significant water losses – are constantly being reported as the existing municipal infrastructure starts to fail. Currently most municipalities charge between R3,80 and R4,70 per kilolitre of water. He says that once the municipal infrastructure needs are included, the charges should rise by an additional amount of between R3,00 and R4,00 providing base charges of between R6,80 and R7,40. South Africacurrently needs to spend at least R1,3-billion to fix infrastructure backlogs and undertake specific maintenance work. Moreover, many cities and towns are unable to account for the significant water losses. Statistics show that Johannesburg ‘lost’ between 35% and 40% of its water last year. The losses were attributed to household wastage and a crumbling and aged infrastructure. Cape Town was unable to account for about 83,4-million kilolitres of water in 2009. Municipalities currently owe South Africa’s water boards R1,7-billion. Source: Property24.com

It's been a while in the making but eventually we're there. The on-line shop for Free Rain Conservation is now up and running. Go check out www.waterfilteringsolutions.co.za.

TASK TEAM TO INVESTIGATE

Pretoria – Cabinet is expected to give direction in the next two weeks on how South Africa will deal with the potential crisis posed by acid mine drainage (AMD) in Gauteng.



Environmentalists have described AMD as the single most significant threat to South Africa’s environment and as heavy rains persisted this week, fears grew that the problem may be exacerbated. But the Water Affairs Department on Thursday said a decision was looming on the matter following an Inter-ministerial Committee (IMC) meeting with Cabinet to discuss the situation.

It comes after Cabinet mandated the Minister of Water Affairs, Edna Molewa, in August to urgently establish a special task team to investigate how the government should respond to reports of acid water drainage in some parts of the country, mainly in Johannesburg.

The team of experts, chaired by Mineral Resources Department Director General, Sandile Nogcina, has handed over a list of recommendations to be considered at the next Cabinet meeting before a public announcement can be made.

“What we can say is that government is very concerned and takes this matter very seriously and at this stage the recommendations have been signed by both DGs in the Department of Water and that of Minerals and is ready for Cabinet discussion. Everyone will know the way forward in a week or so,” said spokesperson Mava Scott.

Nogcina was not immediately available for comment but Scott said once President Jacob Zuma and his executive have had an opportunity to look at the document, a public announcement will be made and all the necessary steps will be taken to avert the AMD situation.

Acid mine water, or water contaminated with heavy metals as a result of mining activities, is reportedly affecting the South Africa’s economic hub Gauteng, with other cases in Mpumalanga, North West and Free State provinces. Reports suggest that this drainage poses health and economic risks for the country.

Scientists predict that if drastic steps are not immediately taken to shut down disused mine shafts and pump out the acid mine drainage, the poisonous water will flow into rivers and low-lying areas at a rate of up to 70 megalitres a day.

Sputnik Ratau, spokesperson for the Environmental Affairs Department, said the recent floods, which have raised the levels of the toxic water in the mines, has been a cause for concern.

“We have always said that there are certain periods when the impact will be major due to rains but we are hoping that the next two weeks will provide direction on this matter – but what cabinet decides, is what cabinet decides,” he said.

As a short-term measure, an amount of R218 million was set aside by the department to fit pumps to avert any situation that might arise. – BuaNews