Water conservation research and legislative news, Part 2
By Ron George,CPD,
President, Ron George Design & Consulting Svcs.
As reported in Part I of this column, which appeared in the August issue of Plumbing Engineer, the Plumbing Efficiency Research Coalition (PERC) identified drain line transport as its first research project. The focus of its laboratory testing will be to verify the feasibility of using programmable flush-o-meter valves or other sources of clear water to clear long drain lines of deposited solids and to measure the relative importance of other systemic variables. To minimize costs, PERC will seek to conduct this test program on a suitable existing test apparatus and is currently in the process of executing a MoU with the AS-Flow committee in Australia. Once the MoU is executed, PERC plans to review this test proposal with the AS-Flow Committee to determine the most cost effective location to conduct this work.
PERC test plan details
The PERC Technical Committee has developed a proposed test plan. Below are the variables that need to be considered for the plan.
Flush volume: Discharge levels of 1.6 gpf (6.0 lpf), 1.28 gpf (4.8 lpf) and 0.8 gpf (3.0 lpf) to be evaluated.
Pipe diameter and material: 4" (100mm) diameter, clear PVC only. (It would be preferable to evaluate 3" and 6" diameter pipe also but, to minimize costs, only 4" diameter pipe will be used for this initial work.)
Toilet discharge flow rate/velocity: Needed to simulate fast acting and slow acting toilets. The PERC committee will use a “surge generator” type device to simulate those flow rates (rather than actual toilet fixtures). This device will allow for more consistent discharge and will maintain the test plan variable pertaining to the discharge more accurately than can be achieved by using actual toilets.
Trailing water: The surge generator will be constructed to allow injection of the solids at various points that result in a high volume of trailing water (70%), typical of fast acting toilets and a lower volume of trailing water (20%), typical of slower acting toilets.
Test media: Soy bean paste (miso paste) will be used to simulate solid human waste. This test media has been used extensively to test toilets to various flush performance tests, including the current U.S. EPA WaterSense specification for gravity flush toilets in the United States and has achieved good acceptance in the industry as an appropriate test media. Two-ply toilet paper will be used.
The following assumptions pertaining to flush discharges into the test apparatus will be applied:
• a 3:1 ratio for solid and liquid waste flushes
• a 50/50 “male to female” ratio
• All males use urinals, not toilets, for liquid waste.*
• No other long duration flows (showers) are available to assist the toilet. (This is because in greywater systems, shower water will be collected for re-use)
• Urinals do not provide any transport assist (waterless or .125 gpf).
• Males: 33.3% solid waste flushes using miso and toilet paper (four balls @ six sheets each), 0% liquid flushes.
• Females: 33.3% solid waste flushes using miso and toilet paper and 66.7% liquid waste using toilet paper only (four balls @ six sheets).* Essentially, this equates to 50% of the flushes having miso and paper and the other 50% having a lesser amount of paper only.
• The miso loadings will randomly vary between 300 grams, 200 grams and 100 grams for all solid flushes for each round of testing.
• Frequency and volume of clearing flush: The test plan will start using a 1% frequency for the clearing flush set at three gallons (11.4 liters). If successful at clearing the 300 foot (90 meter) test apparatus at these levels, no additional testing will be required. If not, evaluation at 2% frequency or at higher flush volume may be required. It will be up to the test engineer to determine whether those values need to be revised once we begin testing, based on observation.
*The above assumptions are not provided to simulate reality in all cases but rather to provide an assumed worst-case scenario.
AWE and ACEEE release water-energy blueprint
For the past 30 years, strategies to conserve and increase the efficiency of energy use have been widely pursued, in parallel with comparable water efficiency efforts. For the most part, efforts to conserve water and energy have not been coordinated in a coherent, collaborative manner. Today there is a growing realization that these separate activities could realize significant benefits from coordination.
Recognizing this need for collaborative action, the Alliance for Water Efficiency (AWE) and the American Council for an Energy-Efficient Economy (ACEEE) secured a grant from the Turner Foundation to bring these two communities together to establish a blueprint for future joint efforts and to envision a policy agenda that could drive actions at the federal, state, local and watershed levels.
The blueprint addresses three broad elements: policy/codes, research and programs. In developing it, AWE and ACEEE have analyzed and consolidated contributions from more than fifty leaders from across the energy and water efficiency communities. The goal of this blueprint and policy agenda is to provide a framework for collaborative action, funding and policy development.
The blueprint strives to learn from the experiences of both the energy and water communities, building on existing policies, programs and relationships. It also contains a policy agenda describing the opportunities available for policymakers at every level of government. The link between energy and water has not received the amount of research and policy attention that it deserves.
Water efficiency legislation introduced in the 112th Congress
The authorization of the EPA’s WaterSense program is at the heart of legislation introduced in late May by New Jersey representative Rush Holt. H.R. 1967, The Water Advanced Technologies for Efficient Resource Use Act of 2011, the WATER Act, takes a “comprehensive approach to boost jobs to install sell, and manufacture water efficient products and services.” It mirrors the provisions that were included in H.R. 2368 (the Holt-Miller WaterSense authorization bill) and H.R. 2454 (the 2009 Waxman-Markey Climate bill) from the 111th Congress and provides for: authorization of the WaterSense program; grants to establish or expand local programs that offer rebates or vouchers to consumers that purchase water efficient products and services; federal agencies to purchase cost effective, water-efficient products.
The legislation includes $50 million in funding for the retrofit incentive program. The bill has been referred to several House committees.
WaterSense, launched in 2006, is the EPA partnership program that seeks to protect the future of our nation’s water supply by promoting water efficiency and expanding the market for water efficient products and services.
Motivation for consumers and industry
Rebates and vouchers encourage consumers to purchase water efficient fixtures such as faucets and toilets. This would create jobs for the plumbers and contractors that install these products and boost jobs in manufacturing them. According to the AWE, these programs would create at least 18 jobs per million dollars of investment. This compares to the approximately 14 jobs created per million dollars of investment in construction, as calculated by the Congressional Research Service. Sales of water efficient products would be increased further through federal procurement of these fixtures, resulting in the creation of installation, retail and manufacturing jobs.
These economic benefits would reap environmental ones as well. If only one out of every 100 American homes retrofitted their homes with water-efficient fixtures, we would save enough energy to power about 9,100 homes for an entire year and avoid adding 80,000 tons of greenhouse gas to the atmosphere.
GAO report identifies the high energy costs of water and wastewater treatment
A Government Accountability Office (GAO) study reports that energy costs to run city water and wastewater systems consume up to half of municipalities’ energy bills, According to the study, many cities recognize that they allocate 30 to 50 percent of their energy budgets to water and wastewater systems, but they fail to use efficient technologies and equipment, upgrade infrastructure or adopt water conservation measures.
In many cities, the costs to meet regulatory standards for water quality testing and the needs of other city departments override the need for appropriating money to redesign water treatment plants or utility infrastructures to cut water and wastewater system energy costs. I saw this firsthand when the water and sewer board I served on decided not to replace old clay tile sewers that caused a significant infiltration of stormwater and groundwater into the wastewater treatment plant during wet weather. The board chose to build wastewater ponds for diverting the excess flows and treated the storm surge flows after the storm event.
DOI identifies increased risks in western U.S.
The United States Department of the Interior (DOI) has released a report that assesses climate change risks and how these risks could impact water operations, hydropower, flood control and fish and wildlife in the western United States. The report to Congress represents the first consistent and coordinated assessment of risks to future water supplies across eight major reclamation river basins.
The report shows several increased risks to western United States water resources during the 21st century. Specific projections include: a temperature increase of five to seven degrees Fahrenheit; a precipitation increase over the northwestern and north-central portions of the western U.S. and a decrease over the southwestern and south-central areas; a decrease for almost all of the April 1 snowpack; a standard benchmark measurement used to project river basin runoff and an eight to 20% decrease in average annual stream flow in several river basins, including the Colorado, the Rio Grande and the San Joaquin.
In addition to drain line transport research concerns, we must also remember that reducing flows at showerheads to flows below two gpm can significantly impact the ability of the shower control valve to maintain a safe outlet temperature. This can lead to thermal shock and scalding incidents, especially on older-style non-pressure or temperature compensating type shower controls and on shower controls without a check valve to limit crossover flow from hot to cold. Remember we must save water wisely.
Ron George is president of Plumb-Tech Design and Consulting Services LLC. He has served as chairman of the International Residential Plumbing & Mechanical Code Committee. Visit www.Plumb-TechLLC.com, email Ron@Plumb-TechLLC.com or phone 734/755-1908.