10 Water Quality Products

W ith drinking water becoming scarcer due to drought in highly popu-

lated areas and drinking water sources becoming more polluted, both indi-vidual homeowners and businesses are becoming aware of the need for drinking water conservation. This brings to mind the old saying, “reduce, reuse, recycle.”

While the thought of drinking recycled water may turn off many consumers, in a way we have been drinking recycled water for centu-ries. The water, or hydrological, cycle describes how water constantly changes between various states above and below the Earth’s surface, which is basically nature’s way of recycling. The mass volume of water on Earth is nearly the same as it was millions of years ago. It is the form in which the water exists, as oceans, rivers and groundwater, which varies over hundreds of thousands of years.

While businesses may look into reducing water use and the possibility of reusing water in production, it is usually done as a cost-saving measure as water rates continue to rise. The average consumer may accept the rate increases or look for simple options to reduce their water use, such as turning off the faucet when brushing their teeth or installing water-saving devices like low-flow toilets. In drought-affected cities, there is a demand for water conservation that involves restrictions on lawn watering.

The amount of freshwater that can be used for drinking is becoming more polluted, so we must act now to ensure clean drinking water. This involves conservation of current water resources and proper management of all water resources, which should include reducing the use of drinking-quality water in applications in which greywater or rainwater could be used instead. The cost of treating water to potable quality is higher, so we should use that water only for consumption.

Non-potable water, such as rainwater and greywater, can be reused to f lush toilets, wash cars, and water lawns and gardens.

In an effort to reduce the amount of water used, some people may opt to collect rainwater for gardening purposes. Of course, rainwater collec-tion works best in areas with high rainfall levels. Some areas of the world, such as the island of Bermuda, rely heavily on rainwater collection for drinking water.

In some areas of the country, collecting rainwater not only saves water, but also helps cities control

storm water and the pollu-tion it may carry. Even

in New York City, in a part of the U.S. that gener-ally receives more than adequate rain-fall to meet its needs, rain-

water detention is mandated for

new building projects above a certain size to help

control storm water runoff. Matt Kaye, president of Better

Waters, a water technology company that actively advises engineering firms and has supplied rainwater reuse technologies for numerous large-scale New York City projects, noted that there has been an expo-nential increase in demand for such systems as construction has returned to robust levels following the recent economic downturn. “Today, unlike before the Great Recession, we are seeing one high-end project after another, whether residential, commer-cial, hotel or mixed use, include rain-water retention and reuse,” Kaye said. “In fact, I think we are at the point that a majority of the most presti-gious new projects underway in New York City incorporate this conserva-tion measure: 99 Church Street, 56 Leonard Street, 855 Sixth Avenue and 205 E. 92nd Street, for instance, are excellent examples. And part of our challenge [in] meeting the principles

of sustainability is to design tech-nology sequences that minimize [the] power required to accomplish the goals of conservation.”

Some cities or sewer districts offer financial incentives for home-owners and businesses by providing a discount on water and sewer bills for those who install rain barrels or rain gardens, or remove or reduce imper-vious surfaces, thus reducing runoff. The payoff can be substantial. In Austin, Texas, for example, businesses can earn up to $40,000 in rebates for installing rainwater harvesting and greywater reuse systems. Rainwater reuse also helps buildings qualify for LEED (Leadership in Energy & Environmental Design) credit, which is a certification for green building growing in popularity.

Rainwater TreatmentBecause rainwater is raw and can

pick up contaminants from the surface it runs over, it is a good idea to assess the water quality. The two biggest quality concerns with rainwater are particulates and microbiological contaminants.

The intended use of rainwater dictates what treatment may be neces-sary. Rainwater that will be used in non-potable applications may not require treatment for microbiological contaminants, but would need filtra-tion to reduce particulates. If rain-water will be used for potable applica-tions, microbiological contaminants must be addressed.

Microbiological contamination can occur easily as water runs from rooftops, which may contain animal excrement. Bacteria also can thrive if water sits stagnant for a period of time. Ultraviolet light is commonly used for rainwater disinfection, but other tech-nologies, such as ozone or chemical disinfection, may be used depending on regulatory requirements and the client’s needs. In some cities, rainwater that will be used for drinking requires a disinfectant that has a residual, like chlorine. It is important to become familiar with local requirements for rainwater collection and treatment before installing these types of systems.

A New Era for Reduce, Reuse, Recycle

Integrating water

conservation

strategies into water

management

By Marianne Metzger

trends water reuse

costs are involved.The need for water conservation

is evident all over the world. The U.S. is just now realizing it is time to change its water management prac-tices, including encouraging rainwater harvesting and reusing greywater and reclaimed water. Rainwater harvesting

and greywater reuse present oppor-tunities for water treatment profes-sionals to expand their services to meet customers’ water treatment needs, which may not just be for drinking water anymore. wqp

Marianne R. Metzger is vice president

of sales and marketing for CNA Environmental. Metzger can be reached at marianne@cnawater.com or 216.906.3021.

For more information on this subject write in 1002 on this issue’s reader service card.

Recycled Water TreatmentRecycled water, also called

reclaimed water, comes from treating water that normally would be discharged as wastewater—i.e., water from wastewater treatment plants that has been treated. This reclaimed water is mainly used for irrigation and recharging aquifers, but some drought-stricken areas are considering using reclaimed water to supplement dwindling water supplies.

In the U.S., California and Florida are active in utilizing reclaimed water. Irvine Ranch Water District in California was one of the first to approve the use of reclaimed water for in-house non-potable use. The reclaimed water makes up about 21% of the district’s water supply, and is mostly used for irrigation, cooling towers and toilet flushing. To distin-guish between reclaimed water and potable water, purple pipe is used for reclaimed water delivery.

In addition to reclaimed water, there also is greywater, which is wastewater from sinks, showers, dish-washers and washing machines that can be reused on site for non-potable applications like f lushing toilets or irrigation. As expected, drought-affected states California and Texas have regulations in place for the use of greywater, as do New Mexico, Wyoming, Montana and Utah. More states are likely to follow with regula-tions of their own as water conserva-tion becomes more important.

Recycling water can become complex depending on which contaminants are present and the intended end use of the water. Some important things to consider when recycling water are energy and chem-ical costs, as well as size restrictions for equipment.

The first step in any recycling project is to determine what the recy-cled water will be used for. If it will be used for potable purposes, addi-tional treatment will be needed. Then determine what possible contaminants may be present. It is a good prac-tice to have the waste stream tested to identify which contaminants are present and at what levels. For black-water, testing should include bacteria, metals and other inorganics, specifi-cally phosphates, nitrates, biological oxygen demand, chemical oxygen demand and ammonia. Keep in mind that pharmaceuticals likely will be present in wastewater, and these may be regulated in the future. Once you have a profile of the water quality, you can begin to consider what treat-ment options are available and what

A New Era for Reduce, Reuse, Recycle

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