water efficiency MANUAL

for Commercial, Industrial, and Institutional Facilities

B Y :

North Carolina Department of Environment and Natural Resources North Carolina Division of Pollution Prevention and Environmental Assistance North Carolina Division of Water Resources Land-of-Sky Regional Council - WRATT Program Editor’s note:

I’ve inserted full table pages in this version to supplement the charts that failed to transfer properly to PDF. Each additional page will display immediately in front of the corresponding damaged page. water efficiency MANUAL

for Commercial, Industrial, and Institutional Facilities

A joint publication of the Division of Pollution Prevention and Environmental Assistance and Division of Water Resources of the North Carolina Department of Environment and Natural Resources, and Land-of-Sky Regional Council.

August 1998

The information contained in this publication is believed to be accurate and reliable. However, the application of this information is at the reader’s own risk. Mention of products, services, or vendors in the publication does not constitute an endorsement by the State of North Carolina, nor the Land-of-Sky Regional Council. The information contained in this publication may be cited freely.

State of North Carolina James B. Hunt, Jr., Governor Wayne McDevitt, Secretary of the Department of Environment and Natural Resources Gary Hunt, Director of the Division of Pollution Prevention and Environmental Assistance John Morris, Director of the Division of Water Resources

Printed under contract with the Land-of-Sky Regional Council, Asheville, North Carolina.

Printed on recycled paper. When to Use This Guide

Now, to determine what you can do reduce water use, improve efficiency, and save money in your operations.

As you plan and budget for next year, to determine what programs, equipment, and employee participation will be necessary to use water more efficiently.

Before you purchase any new water-using domestic fixtures, cooling, heating, process, landscaping, and facility support equipment and service contracts.

Before you seek buy-in and support from your management, main- tenance, and production personnel. They also should read this manual.

Before any facility upgrading, new construction, processing expansions, and new product manufacturing.

During unforeseeable water shortages, drought conditions, or voluntary/mandatory water conservation requirements. Contents

1 Reasons for Water Efficiency Efforts ...... 8 2 Sound Principles of Water Management ...... 12

3 Conducting a Successful Water Efficiency Program ...... 20

4 Water Management Options...... 30 Sanitary/DomesticUses ...... 30 Cooling and Heating ...... 41 Landscaping ...... 50 Kitchen and Food Preparation ...... 61 Cleaning, Rinsing, and In-process Reuse ...... 67

5 Industry Specific Processes ...... 74 Textile ...... 74 Food ...... 82 Metal Finishing ...... 93

6 Auditing Methodology and Tools ...... 100

7 Resources ...... 109

References ...... 114 Acknowledgements

The North Carolina Department of Environment and Natural Resources (NCDENR) would like to acknowledge the following people and organizations that have contrib- uted to the development, review, and printing of this manual.

North Carolina Division of Pollution Prevention and Environmental Assistance Terry Albrecht John Burke Craig Coker Sharon Gladwell Eric Horton Sharon Johnson David Williams

Land-of-Sky Regional Council, Waste Reduction and Technology Transfer Program Rodger Ambrose Don Hollister Ralph Jeaggli Steven Moody Bob Schornstheimer Elizabeth Teague Jim Stokoe

North Carolina Division of Water Resources Don Rayno Tony Young

North Carolina Department of Environment and Natural Resources, Public Affairs Bryan Bass

Jennifer Ball, Regional Water Authority, Asheville, North Carolina Laura Bennett, Grove Park Inn, Asheville, North Carolina Kim Colson, North Carolina Division of Water Quality, Raleigh Brent Smith, North Carolina State University, School of Textiles, Raleigh Kurt Thompson, Hughes Supply, Charlotte, North Carolina

NCDENR also wants to acknowledge the State of California’s Department of Water Resource for the use of portions of its publication, “Water Efficiency Manual for Business Managers and Facility Engineers,” and to the United States General Services Administration for the use of portions of it’s guide, “Water Management: A Compre- hensive Approach for Facility Managers.”

Estimated Water Use in North Carolina

700

600

500

400 Self-Supply 300 Public Supply

200

Million Gallons per Day 100

0

Domestic Industrial Commercial

Irrigation/livestock Chapter 1

Reasons for Water Efficiency Efforts

FIGURE 1 1 Estimated Water Use in North Ca 700 600 500 400 300 200 100 0 Million Gallons per Day

k

Domestic Industrial Commercial

Irrigation/livestoc

Source: United States Geological Survey, 1995.

Water Issues in percent for that same period. In the future, maintaining adequate water North Carolina supplies will require better planning by North Carolina is fortunate in having water systems and more efficient water generally abundant water resources. use by all users. These resources must meet ever increas- ing water supply demands as North Certain areas of the state are already Carolina continue to grow at impressive facing water supply planning challenges, rates. From 1990 to 1997, statewide particularly the coastal plain. In the population increased by almost 800,000 central coastal plain, ground water levels to 7,428,194, an increase of 12 percent. have dropped dramatically in response to Some areas of the state actually experi- increased pumping, possibly limiting the enced populationsuccessful increases of 20 water to 30 efficiencyavailable ground program water supply for future

8 Public Water Supply Uses in North Carolina

Bulk Sales 9% Unaccounted for Residential 10% 38%

Non Residential 43% Chapter 1 use. Elsewhere across the state, numerous water systems are experiencing demands Benefits of Water Efficiency Programs that are approaching their available supply. Some situations are due to limited water resources; others are due to inad- equate water treatment capacity to meet n Reduced Water Demand peak water needs. Regardless, their ability Generally faster, cheaper, and easier to produce additional potable water is constrained. than supply-side programs.

According to the University of North n Water and Wastewater Carolina Water Resources Research Institute (WRRI), approximately 4 million Treatment Saving North Carolinians rely on ground water Reduces costs and defers plant for water supply, and about 3.2 million expansion. depend on surface water. Excluding water use by thermoelectric power plants, 1333 n million gallons per day (mgd) of surface Less Environmental Impact water and 535 mgd of ground water are Due to less surface and subsurface withdrawn to meet water domestic, withdrawals. commercial, industrial, mining, irrigation, and livestock demands. Of this 1868 mgd n Sustained Water Quality total demand, approximately 769 mgd are delivered by public water supply systems. Reduces groundwater’s contami- The remainder is self-supplied. nant intrusion and curtails demand for new supplies that are of lower Industrial, Commercial, and quality. Institutional Water Use Information in the 1992 Local Water Supply Plans indicated non-residential uses of water, consisting of commercial, industrial, FIGURE 2 and institutional sectors, that totaled 322 mgd. This Public Water Supply Uses in North Ca represents about 43 percent of the average Bulk Sales daily demand of the 9% systems submitting plans. (See Figure 2.) Commercial, Unaccounted for Residential industrial, and institutional 10% 38% water demands can make up a larger percentage of total demand for some Non Residential municipal water systems. 43% These “non-residential” uses can have a significant Source: 1992 Public Water Supply Plans, North Carolina Division of Water Resources.

9 Chapter 1

tion/efficiency programs. A common target of such programs is reduction and efficiency vs. conservation management of peak water demands. These programs are intended to extend “Water efficiency” means using improved technologies and the life of existing raw water supplies, practices that deliver equal or better service with less water. For postpone investment in infrastructure example, the use of low flow faucet aerators can be more powerful expansions, and minimize the impacts of than no aerators for washing hands. “Water conservation” has been water shortages such as droughts. Benefits associated with curtailment of water use and doing “less” with less of water efficiency programs include water, typically during a water shortage, such as a drought. For reduced water demand, savings in water example, minimizing lawn watering and automobile washing in and wastewater treatment costs, reduced order to conserve water. Water conservation also includes day-to- environmental effect, and protection of day “demand management” to better manage how and when water high quality water sources. is used, so it is common to hear the words “water conservation” used synonymously with “water efficiency.” Water rate structures can greatly influ- ence efficiency efforts. The feasibility of implementing efficiency options depends effect on local water demands. In the on the analysis of the expected payback 1992 local plans, non-residential demand period, a key component of which is the accounted for over half of average daily cost of water. Trends during the past 10 demand for 87 systems, with 29 systems years show many municipalities are having non-residential demand at least 70 moving away from traditional “declining percent of average demand. block” rate structures which charge less per unit as users consume more. Alterna- The commercial and industrial sectors tive rate structures, such as “uniform” and also use a great deal of water that is self- “increasing block” make efficiency mea- supplied from surface and ground water sures more economically advantageous. sources. The USGS estimated these Still, about half of large municipalities use sectors used 377 mgd of self-supplied water declining block rates which offer little in 1995 (excluding thermoelectric power economic incentive for conservation. uses). The commercial sector accounted for about 8 mgd of that total. The min- In response to water supply issues that ing, irrigation, and livestock sectors of the arose during serious droughts in the late economy also use self-supplied water. In 1980s, North Carolina now requires each 1995, mining used 16 mgd, irrigation used local government water system to prepare 239 mgd, and livestock used 297 mgd a local water supply plan and to update from ground and surface water sources. that plan at least every five years. Local water supply plans include evaluations of Local and State Responses current and future system demands, current and future water supplies, and an to Water Supply Issues accounting of water use by sector for the As a result of increasing water supply reporting year. The preparation of these demands, municipalities and water and plans provides system managers and sewer districts are implementing water community officials the opportunity to efficiency programs. These programs evaluate the ability of their water system range from including water efficiency tips and supply sources to meet current and in water bills to hiring staff to actively future demands. promote and implement water conserva-

10 Chapter 1

When evaluating these water supply achieved billions of gallons of accumula- plans, the Division of Water Resources tive water savings and have proven to be (DWR) is encouraging systems for which cost effective to both public and private average daily demands exceed 80 percent sectors. Programs include activities such as of their available supply to develop a plan on-site audits, guidebooks, seminars, to manage and meet future demands. conservation planning, employee educa- More than 500 systems submitted water tion, advisory committees, trade shows supply plans for the calendar year 1992. expositions, awards, financial incentives/ For 1992, about 10 percent of these assistance, ordinances, regulations, re- systems had demands that exceeded 80 search studies, and industrial reuse pro- percent of supply. However, more than 20 grams. While these programs have been percent of these systems project demand well developed in various locations in exceeding 80 percent of supply by 2020. California, Phoenix, Tucson, Seattle, Boston, and New York City, only a few In evaluating options for meeting future programs exist in North Carolina. demand, DWR strongly encourages systems to incorporate ways to use avail- Roles and Responsibilities able water supplies more efficiently. in Water Efficiency Coordinated Efficiency When public water supply systems are reaching capacity limits, both public and Efforts private sectors have important roles to Conservation/efficiency efforts need to play. Public water conservation programs be coordinated among the municipalities must address leaks and “unaccounted for” and districts that share river basins and water use, drought planning, water aquifers. North Carolina has been taking efficiency awareness and communications, steps to improve the accountability and and residential program coordination; coordination of water use in the state. In enact appropriate billing structures; and 1989, the General Assembly passed a bill serve as role models for water use effi- that addresses local and state water supply ciency in public facilities. planning. Several bills and rules related to water management have been and are The private sector also should think about being passed and adopted. They include conserving water. When industrial and the reuse of reclaimed wastewater, water commercial facilities use water more supply watershed protection, the Water efficiently, it saves money while helping Use Act, the Coastal Area Management the environment. Many facility managers Act, and Basinwide Water Quality Plan- may view water efficiency measures as ning. actions necessary only in droughts, but there are many important reasons to Water Efficiency continually use water efficiently. These driving factors include: preservation of Demand-Side Programs quality water supplies, both surface and Nationally, water efficiency programs for groundwater; cost savings in water, sewer, the commercial and industrial sectors chemical treatment, and energy; produc- have been established in several state and tion expansion without increased water local water resources departments for use; and delaying the need for new water many years. These programs have supplies.

11 Chapter 2

Sound Principles of 2 Water Management Optimizing facility water use means more than conducting an in-plant study and preparing a report. Water efficiency measures must be viewed holistically within a business’ strate- gic planning. Firms that use water more efficiently now will have a competitive advantage over companies that choose to wait. A successful program must prioritize needs, set well- informed goals, establish current performance minimums, and carefully plan a course for action. Consider these prin- ciples when establishing water efficiency initiatives.

Categories of Water Efficiency Measures

n Reducing losses (e.g. fixing leaking hose nozzles) n Reducing overall water use (e.g. shutting off process water when not in use) n Employing water reuse practices (e.g. reusing washwater)

12 Chapter 2

changing behavior vs. equipment

Equipment changes may be viewed as a “permanent fix” to achieve water efficiency. Changing employee behaviors, such as an operating procedure, may be viewed as a quick and inexpen- sive way to achieve similar savings without up-front capital expense. In reality, both the technical and human side of water management issues must be addressed. Consistent training and awareness in combination with proper tools and equipment will achieve more permanent water savings.

Prioritizing Needs and n Any program should include water Setting Goals supply and wastewater utilities in Before considering any water efficiency the process. Involving utilities can measure, management must first ensure help align water use goals for both water use performance is consistent with: water users and suppliers. Utilities may have demand-side manage- n Public health sanitation require- ment concerns such as meeting ments such as the United States summer’s increased demands or Department of Agriculture meeting a peak hourly demand. (USDA), the Food and Drug These specific concerns can be Administration (FDA), and state factored into a facility water and local health regulations. management program. n Environmental requirements such n Anticipate increased water and as water quality reuse rules and wastewater service costs when criteria. considering options. Ask utilities n Other health and safety require- to provide any expected increases. ment, such as state and local n Anticipate future increases in building codes and fire safety production or number of employ- codes. ees that will influence water n Customer quality expectations, consumption. such as product cleanliness specifi- n Use total cost accounting methods cations. to perform economic comparison of water-efficient techniques. Closer examination of the above require- Consider water and wastewater ment may lead to more water-efficient costs, on-site pretreatment costs, ways to achieve and exceed health, safety, marginal cost for capacity expan- and customer quality requirements. With sion, and energy savings (especially the above priority established, consider heat). the following suggestions before embark- n Encourage water and wastewater ing on program goal setting. utilities to provide rebates and

13 Chapter 2

Self-Assessment Checklist

What efforts has your facility already made in water efficiency? Several questions for facility managers are listed below to help gauge a facility’s present water efficiency performance.

Top Management Commitment and Resources

n Is water efficiency included in the company’s environmental policy statement? n Are water efficiency responsibilities delegated? n Are quantitative goals established and tracked? n How are water efficiency goals communicated to employees? n What incentives and feedback loops exist for employee participation, suggestions, and increased awareness? n Has your facility taken advantage of available help and resources from your utilities, assistance programs, vendors, or consultants?

Water Efficiency Survey

n Do you know the actual breakdown of your water uses: cooling and heating, domestic uses, process rinsing, cleaning activities, kitchens, laundries, landscaping, water treatment regeneration, evaporation, leaks, and others? n Do you know your life cycle water costs for supply water, wastewater treatment, sewer/discharge, and heat and mechanic energy losses? n Are you doing simple things such as leak inspections, eliminating unnecessary uses, and using timers? Are these practices institutionalized?

Identifying Opportunities - Target Areas for Water Reduction

DOMESTIC

n Are code conforming 1.6 gpf commodes, 0.5-1.0 gpm faucet aerators, and low flow 2.5 gpm showerheads in use?

HEATING/COOLING

n Has once-through cooling water used in air conditioners, air compressors, vacuum pumps, etc., been eliminated with the use of chillers, cooling towers, or air cooled equipment? n Has blow-down/bleed-off control on boilers and cooling towers been optimized? n Is condensate being reused?

CHECKLIST IS CONTINUED ON NEXT PAGE

14 Chapter 2

SELF-ASSESSMENT CHECKLIST CONTINUED FROM PREVIOUS PAGE

PROCESS RINSING AND CLEANING

n Have you considered improved rinsing techniques such as counter current systems, sequential use from high quality to lower quality needs, conductivity flow controls, improved spray nozzles/ pressure rinsing, fog rinsing, or agitated rinsing? n Is water cut off when not in use by flow timers, limit switches, or manually? n Is the life of an aqueous bath being maximized via filtration and maintenance control? n Are “dry clean-up” practices used instead of hosing down, and first pass pre-cleaning conducted with squeegees, brushes, or brooms?

ON-SITE WATER REUSE

n Is water quality matched with water quantity? n Have reuse applications been examined for process water, landscaping irrigation, ornamental ponds, flush water, and cooling towers?

LANDSCAPING

n Are low-flow sprinklers, trickle/drip irrigation, optimized watering schedules and water place- ment, preventative maintenance, and xeriscaping techniques in place?

KITCHENS

n Are “electric eye” sensors for conveyer dishwashers installed? n Have new water and energy efficient dishwashers been examined?

Water Efficiency Action Plan

n Have you performed a cost analysis on water efficiency opportunities? n Do you have a prioritized implementation schedule? n Are water users informed of the changes and communication channels open for feedback?

Tracking and Communicating Results

n Do you post monthly water usage rates to employees and management? n Are your water efficiency achievements being recognized in case study articles, media coverage, mentoring to other businesses, business environmental exchange programs, or in award programs?

15 Chapter 2

other financial incentives to offset self assessments, statistical process control, the cost of implementing a water ISO 9000 and 14000, process analysis, conservation measure. Use the quality circle, and many others. efficiency/conservation plan as a Benchmarking, too, can be an important bargaining point. TQM tool to improve water use effi- n Program goals should not only ciency. Benchmarking is a process of consider the technical side for comparing one’s own operational perfor- water efficiency, but also should mance to other organization’s to become consider the human side, such as “best in class” and make continual im- changing behaviors and attitudes provements. Benchmarking is more than toward water use. simply setting a performance reference or n Do the simple tasks first to gain comparison, it is a way to facilitate learn- acceptance and positive feedback ing for continual improvements. The key for the program. to the learning process is looking outside one’s own business to other industry Use internal and external benchmarking sectors that have discovered better ways of techniques to help optimize water con- achieving improved performance. sumption. Benchmarking can be performance based, process based, or strategic based Using TQM and and can compare financial or operational performance measures, methods or Benchmarking Tools practices, or strategic choices. Facility managers have a variety of Total Quality Management (TQM) tools to help Five Steps of a plan, develop, and implement water efficiency measures. These tools include Benchmarking Process Planning Managers must select a process to be benchmarked. A benchmarking team should be formed. The process of benchmarking must be thoroughly understood and documented. The perfor- Step 5 Step 1 Adapt Plan mance measure for the process should be established (i.e. cost, time, and quality).

Search Benchmarking Process Information on the “best-in-class” per- former must be determined. The infor-

Step 4 mation can be derived from the Analyze Step 2 company’s existing network, industry Search experts, industry and trade associations, publications, public information, and Step 3 other award-winning companies. This Observe information can be used to identify the best benchmarking partners with which to begin cooperative participation.

16 Chapter 2

Observation into action. The findings of the The observation step is a study of the benchmarking study must be communi- benchmarking partner’s performance cated to gain acceptance, functional goals level, processes and practices that have must be established, and a plan must be achieved those levels, and other enabling developed. Progress should be monitored factors. and corrections in the process made accordingly. Analysis In this phase, comparisons in perfor- The benchmarking process should be mance levels among the facilities are interactive. It should also recalibrate determined. The root causes for the performance measures and improve the performance gaps are studied. To make process itself. accurate and appropriate comparisons, the comparison data must be sorted, Common Water Efficiency controlled for quality, and normalized. Measures Adaptation As businesses managers seek to gauge their own performance in areas concern- This phase is putting what is learned ing water management, data from a throughout the benchmarking process

FIGURE 3 Most Commonly Implemented Efficiency Measures by Business and Industry

Recycle Process Water Improved Maintenance to Replace Miscellaneous Equipment and Parts Use Domestic Water Efficiency Techniques - Ultra low flush toilets, urinal, faucet aerators, low flow showerheads, etc. Change Operational Practices Adjust Cooling Tower Blowdown Reduce Landscaping Irrigation Time Schedules Adjust Equipment Repair Leaks Install Spray Nozzles Install and/or Replace Automatic Shut-Off Nozzles Reduce Dishwasher loads Turn Off Equipment when Not in Use

(Source: Metropolitan Water District of Southern California - Survey of 902 Commercial, Industrial, and Institutional Facilities, November 1997.)

17 Chapter 2

number of water efficiency programs can Typical Water Balance be used to determine “best in class” techniques. Figure 3 shows the most Findings common water efficiency measures used by a variety of commercial, institutional, Understanding water use at a facility is and industrial facilities that participated imperative to appropriately prioritize in water use audit programs. areas to focus time and resources. The following graphs (Figures 4 - 9) show examples of water use distribution (water FIGURE 4 balances) for common commercial,

Office Water Balance institutional, and industrial settings. Manufacturers sampled in Figure 5 include metal fabricators, rubber prod- Unaccounted for Leaks/Other Misc 9% ucts, aeronautical, and cardboard products <1% manufacturers. Data are based on a 1991

Landscaping Domestic Non-residential Water Audit Program 22% 40% conducted in Denver, Colorado. Each Kitchen facility should determine its own unique 1% water balance to best target opportunities. Once-Through Cooling Cooling/Heating 2% 26%

FIGURE 5

Manufacturers Water Balance

Other Misc. Unaccounted for 3% 9%

Leaks Domestic 3% 16% Landscapiing 5% Process Uses 8% Kitchen 1% Washing & Sanitation Cooling/Heating 1% 47% Once-Through Cooling 7% FIGURE 6

Food Processors Water Balance

Unaccounted for Other Misc. 6% Domestic 1% 3% Cooling/Heating Leaks 19% 2% Process Uses 13%

Once-Through Cooling 14%

Washing & Sanitation 42%

18 Chapter 2

FIGURE 7

School and Universities Water Balance

Leaks Unaccounted for 1% 4%

Landscaping 30% Domestic 48% Kitchen 4% Laundry 3% Once-Through Cooling/Heating Cooling 5% 5% FIGURE 8

Hotels and Motels Water Balance

Unaccounted for 10% Kitchen 6% Domestic Laundry 42% 17%

Washing & Cooling/Heating Sanitation 7% 18%

FIGURE 9

Health Care Facilities Water Balance

Other Misc. 2% Unaccounted for Landscaping 5% 4% Process Uses 7% Domestic Kitchen 40% 5%

Laundry 12%

Washing & Sanitation Cooling/Heating 5% Once-Thorugh 11% Cooling 9% The guidance presented in this chapter provides the framework to pursue water efficiency measures. Chapter 3 presents a six-step process to guide facility staff through the details of enacting a successful water efficiency program.

19 Chapter 3 Conducting a Successful Water 3 Efficiency Program

A successful water efficiency program other cost-reduction program or environ- should begin with a well-thought plan. mental management system. Regardless Crucial to the development and use of the driving factors, a heightened aware- this plan are management’s commitment; ness and road map to water efficiency sufficient technical staff and financial opportunities and cost savings will help resources; employee awareness and management make sound choices to participation; and well-publicized results. optimize operational efficiency, improve Water efficiency measures may very likely economic competitiveness, and conserve be just one part of an integrated energy quality water resources for the future. management, pollution prevention, or

Steps for a successful water efficiency program

successfulStep 1 - Establish water commitment efficiency and goals program successfulStep 2 - Line waterup support efficiency and resources program successfulStep 3 - Conduct water a water efficiency audit program successfulStep 4 - Identify water water efficiencymanagement options program succStep essfu5 - Preparel water a plan efficiencyand implemention program schedule successfulStep 6 - Track water results and efficiency publicize success program

20 Chapter 3

Step 1 water efficiency measures for further improvements. Establish Commitment 2. Establish a budget, and and Goals procure funding. At first, water efficiency goals may be 3. Evaluate regulatory con- qualitative and included in statements of straints and local water commitment, environmental policies, supply issues. budgetary planning, or other external 4. Seek outside funding, awareness measures. Initial commitments grants, and available should allocate staff and resources to technical assistance. assess the current water use baseline and 5. Coordinate a water efficiency explore water efficiency opportunities. audit. With additional 6. Establish implementation criteria information, for designing water efficiency realistic goals of measures. quantitative water 7. Develop a plan. efficiency can be 8. Encourage employee participation established. For and create awareness. example, goals 9. Oversee implementation of could include efficiency measures and activities. establishing a percent reduction goal in 10. Periodically review program overall water consumption (such as a 10 progress and make modifications percent overall reduction in water use for continuous improvement. next fiscal year) or establishing a gallon- per-year reduction goal in water consump- Achieve Employee Participation tion (such as reducing consumption by The importance of employee awareness 20,000 gallons per year). Even better goal and cooperation in the water conserva- setting uses industry benchmarking tion program cannot be over emphasized. information based on an operating index (such as gallons per pound of product n Establish and promote the water manufactured or gallons consumed per efficiency/conservation program client served). Remember, goal setting is for employees. Provide back- an on-going process requiring periodic ground information about the review and revisions for continual im- water conservation policy and its provement. implications for company opera- tions. Step 2 n Initiate the employee awareness program with a letter directed to Line Up Support and Resources each employee from the head of Designate a Conservation Manager the organization, such as the A conservation manager, coordinator, or CEO, president, owner, mayor, team leader also may have responsibilities city manager, governor, or chief for energy management and or environ- administrator. The letter should mental management. The conservation describe the established conserva- manager should: tion policy, identify the water efficiency coordinator, express full 1. Review effectiveness of present support for the plan, and invite

21 Chapter 3

feedback. priate methods to transmit poli- n Emphasize the need for individual cies, programs, ideas, announce- responsibility as part of a team ments, progress reports, and news effort to achieve efficiency and of special achievements. environmental goals. n Schedule staff meetings to com- n Establish a “water-saving idea box” municate the organization’s water- and encourage employees at all conservation plan and progress in levels to submit water-saving ideas. water savings. Respond to each suggestion n Establish charts that graphically offered. show the financial savings. n Use audio-visual programs, outside Communicate Water speakers, and other means for Conservation Awareness employee meetings. n Post water-conservation stickers, n Incorporate water conservation signs, and posters in bathrooms, policies and procedures into kitchens, cafeterias, conference employee training programs. rooms, and other places where n Use bulletins, e-mail, newsletters, employees congregate. paycheck stuffers, or other appro-

Check out these water efficiency Internet sites

Waterwiser – Water Efficiency Resources http://www.waterwiser.org

Water Librarian’s home page http://www.wco.com/~rteeter/waterlib.html

Division of Pollution Prevention and Environmental Assistance http://www.p2pays.org

North Carolina Division of Water Resources http://www.dwr.ehnr.state.nc.us/home.htm

North Carolina Division of Water Quality http://h2o.ehnr.state.nc.us/

VendInfo - Pollution Prevention Vendors http://es/epa.gov/vendors world wide web

22 Chapter 3

Establish Employee Incentives customers with leak-detection programs or water audits of n Recognize and reward those facilities. Some utilities nationwide employees who submit water- offer rate reductions and financial saving ideas. incentives for water efficiency n Include water consumption investments. measures in employees’ job n Participate in any water conserva- performance reviews. tion advisory group, or similar n Motivate employees by rewarding organization, generally sponsored them with a percentage of the by local water authorities. If such a first year’s direct savings. group does not exist, help the n Allocate water and sewer costs to utility establish one. each individual department to n Consider hiring private consult- create responsibility for water ants to help develop water effi- efficiency. ciency programs and conduct n Organize and promote competi- audits. Ensure professionals have tion between shifts. adequate experience and proper certifications for their field (i.e., Use Outside Assistance Certifications for landscaping Outside organizations are available to include certified landscaping assist with water conservation activities. irrigation auditors, certified Their assistance should be solicited irrigation designers, and certified wherever feasible as a resource for the irrigation contractors.). promotion of water conservation. Some n Work with local wastewater suggestions are listed below. utilities and wastewater discharge regulators. As conservation n Take advantage of free or low cost measures are put into effect in technical assistance organizations industrial processes, wastewater such as EPA’s Water Alliances of pollutant concentration may Voluntary Efficiency (WAVE) increase, although the same mass Program, North Carolina Division of these pollutants have stayed the of Pollution Prevention and same. These increased concentra- Environmental Assistance, North tions may alter a facility’s ability to Carolina State University’s meet local, state, or federal (NCSU) Industrial Extension effluent discharge limits. Request Service, NCSU’s Industrial Assess- wastewater regulators to recognize ment Center, Waste Reduction conservation efforts by amending and Technology Transfer program the wastewater discharge permits in western North Carolina, and to address total mass of pollutants energy utilities assistance programs instead of concentration levels. (i.e., CP&L and Duke Power). n Water and wastewater utilities are Help Take the Message Home vitally interested in assisting Develop an employee education program customers to conserve water. They that will encourage employees to save can provide information, contacts water at home, as well as in the work- with other industries, and advice. place. Some suggestions are: Water suppliers may even assist

23 Simplified Water Balance at a Manufacturing Facility City Water I IN

Process Effluent / : Domestic OUT $ Effluent OUT + Chapter 3

FIGURE 10

Simplified Water Balance at a Manufacturing Facility

Evaporative Losses

Chiller Parts Cleaning and Rinsing Baths Cooling Tower Makeup

Chiller Manufacturing Area General Washing and Sanitation

Boiler Hot Water Make-up

Process Mixing and Air Compressor Wastewater Vat Cleaning Restro Cooling Treatment Once-through Process Effluent OUT

Water Balance Summary Sources of Water Use Gallons per year Percent of total

Cooling: tower make-up and boiler make-up 7,966,000 38.3 Process use: parts and mixing vat cleaning 3,848,000 18.5 Domestic: faucets, toilets, and showers 3,536,000 17 Once-through cooling: air compressors, and pumps 2,388,000 11 Landscaping 832,000 4 General washing, sanitation, and maintenance 561,600 2.7 Leaks (detected) 416,000 2 Food preparation: dishwasher 312,000 1.5 SUBTOTAL 19,859,000 95.5 TOTAL WATER PURCHASED 20,800,000 100.0 UNACCOUNTED FOR 941,000 4.5

24 Chapter 3

n Offer home water-saving devices manager to employees free or at cost. n Maintenance n Sponsor demonstrations that will n Possible outside auditors educate employees how to water landscapes efficiently, plant seeds Collect Background Site for water-thrifty plants, install low- Information and Records flow plumbing fixtures, and n Water bills (previous full year) – improve water-use habits. Device Note rate structures manufacturers, local hardware n Water meter sizes and locations stores, or your water utility may be n All sources of potable and non- happy to assist with such a pro- potable water gram. n Process sub-metering data n Distribute home water conserva- n Wastewater treatment tion booklets. n Sewer bill n Production process sheet Step 3 n Plumbing diagram Conduct Water Audit to Assess n Irrigation drawing/plan and existing irrigation control pro- Current Water Uses and Costs gram. To identify potential water efficiency n Number of employees opportunities, it is first necessary to gain a n Number of shifts, work, and clean- thorough understanding of the site’s up schedules water uses through a water audit. A water n Facility description – square audit is defined as the process by which all footage, functions uses of water on a site are characterized as n Products and services preformed flow rate, flow direction, temperature, at the site and quality requirement. n Production rates or client service rates Water Balance n List of known water consuming An important task is to construct a water process and uses balance diagram or summary chart, which n Prior water use or energy survey identifies all water uses from their source n (Preventive) Maintenance sched- through the on-site processes, machines, ules. buildings and landscape irrigation to evaporation and wastewater discharge. To Walk-Through Survey account for all uses in the water balance, The next step is to conduct a walk- the total inflow should equal the total through survey with the audit team. Use outflow plus irrigation, evaporation, and direct observation and measurements, other water losses. (See Figure 10.) and ask questions. Talk with equipment operators who may have important first- Select a Water Audit Team hand information. Use the following Include the follow representatives: procedure to conduct the survey.

n Water efficiency coordinator n Identify all water consuming n Personnel familiar with the equipment. operations n Confirm plumbing diagrams. n Facility management/plant n Quantify water flow rates and

25 Chapter 3

usage. Determine the True Cost of Water Use n Determine water quality needs for The true cost of using water may include each process. several factors other than the actual water n Review current water saving utility fees. Examples of costs include measures. water heating, chemical agents, electrical n Observe shift clean-ups (third pumping, on-site pretreatment, and shifts), and process change-overs. related labor. (See Figure 11.) n Also note all water losses, evapora- tive losses, and water incorporated To calculate the dollar in product; excessive water pres- savings resulting sure; and leaks. from reduced water n Judge current water use use, a value for each efficiency and potential for unit of water used each operation. must be derived.

Key areas to check during a walk-through survey

Process and Equipment Use Kitchen Food Cleaning, washing, rinsing Cafeteria uses Metal finishing Dishwashers Painting Ice machines Dyeing and finishing Faucets Photo processing Other Facility Support Reuses Floor washing Product fluming (water transport) Air emission wet scubbers Water use in products Building washing Cooling and Heating QA/QC testing Single-pass cooling Laboratories Cooling tower/chillers Wastewater treatment Boiler, hot water, steam systems Outdoor Uses Air washers Landscaping Boiler scrubber Irrigation Sanitary and Domestic Particulate emission control Toilets Decorative fountains/ponds Urinals Vehicle washing Faucets Personnel Showers Medical

26 Chapter 3

One approach is to divide the total costs 1. Water purchased from utilities. of water used per year by the total Billing normally consists of a fixed amount of water used. For facilities service cost and water rate cost. engaged in production of “widgets,” the The fixed charge should be total cost of water used for a production excluded from the analysis. run should be divided by the total num- 2. Wastewater sewer rate and sur- ber of widgets produced to get a “cost per charges. widget” of water use. 3. Total cost of on-site water soften- ing or treatment before use. In calculating the total cost of water use 4. Cost of energy for heating water. and the many components that go into 5. Total cost of pretreating wastewa- the total cost, current prices of all these ter effluent, including labor, elements is a good starting point. How- chemical, energy, and residual ever, a more meaningful comparison can disposal. be made using future rates and prices for 6. Cost of maintenance personnel these elements after the efficiency mea- performing preventative or sures are put into effect. These major cost reactive maintenance on water elements include: using components.

FIGURE 11

Example Total Water Costs in a Metal Finishing Operation (not heated) Unit Cost Total Unit Cost ($/CCF) Activity ($/CCF) 1 CCF = 748 gallons

City water purchase $1.55 Sewer rate $1.78 Deionized using reverse osmosis Equipment $0.37 Energy $0.97 Labor $1.12 Total deionized water (flexible cost)* $2.46 x 40% Deionized water (flexible cost)* 40% x $2.46 $0.98 Wastewater treatment Sludge disposal $3.45 Treatment chemicals $2.30 Energy $0.22 Labor $5.46 Total wastewater treatment $11.43 WW treatment (flexible cost) 40% x $11.43/CCF $4.57 Total cost of water $8.88/CCF ($11.87/1,000 gallons) If a metal finisher consuming 35,000 gallons per day reduces use by 10%, estimated savings using water and sewer cost only = 250 days/yr x 0.01 x 35,000 gpd x (1.55/784 + 1.78/784) = $389/year

Estimated savings using total cost of water = 250 days/yr x 0.01 x 35,000 gpd x $11.87/1,000 gallons = $1,038/year

*Flexible cost savings of conserved water estimated to be 40 percent of total treatment cost.

27 Chapter 3

7. If water demand is increasing, Step 5 determine the marginal costs of increasing effluent treatment Prepare a Plan and capacity. Implementation Schedule 8. Energy costs for pumping water Develop an action plan that outlines and from wells or pumping water lists all proposed water efficiency measures within the facility itself. resulting from the facility audit. Include the following items in the plan: When comparing efficiency options, first consider reducing consumption of the 1. State the company policy regard- most expensive components of water use. ing conservation and water efficiency, reflecting the commit- ment of company management. Step 4 2. Quantify your goals. Establish the Identify Water Management amount of water to be saved Opportunities in Plant and throughout the entire facility, as well as by each organizational unit. Equipment Also, set deadlines by which these There are at least six general approaches savings are to be achieved. for identifying water-saving opportunities, 3. Summarize all efficiency measures as listed below. These approaches can be identified during the water audit applied to water uses at any site. and by employee suggestions. 4. Evaluate each of these measures. General Approaches for Water- Be sure to include all costs and Saving Opportunities benefits including capital costs, operating costs, projected savings, n Identify unnecessary uses and fix and payback periods. Do not leaks. forget to include cost of energy n Use minimum amounts of water consumption, treatment of water, to accomplish the task. chemical costs, creation of solid n Recirculate water within a process and toxic wastes, and wastewater or group of processes. discharge. n Reuse water sequentially. 5. Prioritize the measures in the n Treat and reclaim used water. following order: n Displace potable water supplies with water from non-potable n Those that are most cost- sources were appropriate. effective and should be put n Install meters at high-flow pro- into effect as soon as possible. cesses and equipment. n Those measures that should be evaluated through a trial This manual provides a detailed discussion period to collect meaningful about water reduction options in chapters 4 data. and 5. n Those measures that are not cost-effective, but could be implemented in times of drought or emergency situa- tions.

28 Chapter 3

6. Identify need for any engineering 1. Encourage company conservation design changes. team members to participate in: 7. Establish the schedule for imple- menting each specific measure. n Community conservation 8. Identify the employee responsible seminars to share program for implementing each measure; results, as well as obtaining continuously monitor the effec- useful information from other tiveness and performance of each campanies’ efforts. measure. n Water conservation commit- 9. Identify funding sources for specific tees sponsored by local water measures that will require capital utilities. expenditure. Consider loans and rebates that may be available from 2. Present savings in relevant terms energy and water utilities. such as dollars, water savings per 10. Review periodically, and revise unit of product, earnings per plan appropriately. share, or annual consumption per household. Step 6 3. Prepare, display, and promote the company’s water conservation Track Results and successes by means such as: Publicize Success Publicize the success of your program. n Display the company’s water Positive publicity promotes good relations conservation results in public with employees, the community, other reception areas. businesses, and organizations that support n Place posters and other exhib- economic development. It also helps to its in public buildings and art stimulate similar water management fairs. efforts. Some publicity options include n Post signs on water-thrifty internal memos, company newsletters, landscapes to identify types of brochures, trade publications, news plants that require little water. releases to local media, letters to public n Once the plan has shown officials, talk radio, and interviews with significant savings, develop a the media. Many water utilities will help public relations program, publicize good results to encourage others including interviews with local to develop similar plans. A good water radio and TV stations and efficiency program is news because it newspapers, about the means more water will be available to the company’s successes. community. 4. Sponsor water conservation Businesses with successful water manage- projects such as a public xeriscape ment programs deserve recognition by demonstration garden. the public. Likewise, the public should be 5. Sponsor water conservation informed that businesses are socially and contests in schools. For example, environmentally responsible partners in encourage students to create the community. These steps can help posters to be displayed in the businesses make their publicity efforts community and at company work more visible and successful: sites.

29 Chapter 4

Water Management Options

4 Sanitary/Domestic Uses Cooling and Heating

Landscaping

Kitchen and Food Preparation

Cleaning, Rinsing, and In-process Reuse

Sanitary/Domestic Uses

Often overlooked are the range from a few percent at a food water and cost savings achiev- processing industry to more than 50 able in the domestic water percent in an office setting. Average daily usage by commercial and domestic demands in commercial/ industrial facilities. While industrial settings range between 20 and water efficiency measures 35 gallons per day (gpd) per employee, should begin with the highest and a savings of 25 to 30 percent in this water use operations such as domestic usage is readily achievable. cooling, cleaning, rinsing, heating, etc., many facilities Toilets miss the easy improvements Americans consume almost 4.8 billion that can be made in domestic gallons of water daily by flushing toilets water devices such as toilets, urinals, sink and urinals. In a business office setting, faucets, and showers. Domestic water use toilet water usage alone can account for at industrial and commercial facilities may approximately one-third of all water used.

30 Chapter 4

FIGURE 12 A number of water efficiency options exist for toilets in most Typical Water Consumption for Toilets facilities constructed before 1994 Years that have not been renovated Manufactured Gravity Tank Style Flush Valve Style recently. Pre-1977 5.0-7.0 gpf 4.5-5.0 gpf The three major types of toilets 1977 to mid 1990s 3.5 (some 5.0 gpf) 3.5 gpf include gravity flush, flush valve, Mid 1990s 1.6 maximum 1.6 maximum and pressurized tank type. Pre- 1977 gravity toilets will consume five to seven gallons per flush (gpf). Pre- 1977 flush valve toilets use 4.5 to 5.0 gallons per flush. Gravity and flush valve Gravity flush toilet style toilets manufactured between 1977 and mid 1990s mostly use 3.5 gallons per flush, although some 5.0 gpf gravity flush toilets continued to be manufactured during that period. (See Figure 12.) rim wash slot The 1.6 Gallons Per steep sides small water pool narrow trap Flush Toilet opening In the 1990s, toilet manufacturers intro- duced ultra-low-flush toilets (ULF) that use 1.6 gallons per flush. Federal regulations require that all toilets manufactured after January 1, 1994, consume no more than were associated with performance prob- 1.6 gpf. Some of the original ULF models lems, but more recent models have improved designs and perfor- FIGURE 13 mance.

Maintenance Checklist for Gravity Flush Toilets Gravity Flush and Flush Valve Gravity flush toilets are the (flushometer) Toilets most common of all toilets. Gravity flush toilets most likely are found in medium- to light- Check for leaks every six months. use business applications.

Encourage employees to report leaks Water efficiency options for promptly. gravity flush toilets include improved maintenance, Adjust float valve to use as little water as retrofit, and replacement possible without impeding waste removal or options. violating the manufacturer’s recommendations. For a maintenance checklist, see Periodically replace valves and ballcocks. Figure 13.

31 Payback for 1.6 gpf Toilet Replacements 1980 to mid 1990, 3.5 gpf tank units

5.0

4.5

4.0

3.5

Users/toilet 5 Users/toilet 8 3.0 Users/toilet 11 Users/toilet 14 2.5 Payback (years) 2.0

1.5

1.0

0.5

0.0 95 105 115 125 135 145 155 165 175 185 195 205 215 225 235 245 255 265 275 285 295 305 315 Installed Cost ($/toilet) Chapter 4

Retrofit years. A plumber should be consulted Retrofit options of gravity flush systems before installing such devices. are most effective on units that consume more than 3.5 gpf (pre-1980s models). For Early closure flapper valves replace the toilets that consume 3.5 gpf or less, existing flush valve in the tank. These retrofit options may hamper toilet perfor- devices are adjustable to optimize perfor- mance or increase maintenance cost. mance and can save 0.5 to 2 gpf. Early Most retrofit options are available for less closing flappers are inexpensive and than $20.

Displacement devices, including bags or bottles, can reduce water Toilet Displacement Bag flow by approximately 0.75 gpf. They function by displacing flush water stored in the tank. The devices are inexpensive and easy to install, but do require regular maintenance. Bricks or other friable objects should never be used as displacement devices because granular contaminants can prevent proper closure of the flapper and damage flow valves.

Toilet dams are flexible inserts placed in a toilet tank to keep 0.5 to 1.0 gallon out of each flush cycle. Dams will last five to six

FIGURE 14

Payback for 1.6 gpf Toilet R 1980 to mid 1990, 3.5 gpf t

5.0

4.5

4.0

3.5

3.0

2.5

2.0 Payback (years) 1.5

1.0

0.5

0.0 95 105 115 125 135 145 155 165 175 185 195 205 215 225 23 Installed Cost ($/toilet)

32 Chapter 4 usually can be installed in 10-15 minutes, Replacements barring other problems with the toilet’s Replacing older commodes with 1.6 gpf mechanisms. models will provide the most water savings. Most 1.6-gpf replacements will Dual flush adapters allow users to use a offer a payback period of less than four standard flush for solids removal or a years. Facilities may achieve quicker modified smaller flush for liquid and payback in these situations: paper. Dual flush adapters have been more popular in Europe than the United n Experience high water and/or States. Dual flush adapters can save sewer costs. between 0.6 to 1.2 gpf. To use this retrofit n Have a relatively high number of option, facility managers should provide users per toilet. user instructions about the proper use of n Currently use high water consum- hese dual flush systems. ing (five to seven gpf) toilets.

Energy Policy Act of 1992

The Energy Policy Act established water efficiency plumbing standards for certain plumbing devices. Prior to 1992, many states and municipalities concerned about water conservation were setting unique standards, which created difficulty for manufacturers and distributors trying to meet these numerous standards. The Energy Policy Act created a set of unified national standards.

Effective January 1, 1994, federal standards set for maximum water usage are:

Toilets 1.6 gpf Urinals 1.0 gpf Showerheads 2.5 gpm @ 80psi Lavatory Faucets 2.5 gpm @ 80 psi Kitchen Faucets 2.5 gpm @ 80 psi

Commercial use of gravity tank type units manufactured between January 1, 1994, and January 1, 1997, could use 3.5 gpf.

The water efficiency standard was established to:

n Preserve and protect water supply source, both surface and groundwater. n Ensure water availability for all beneficial uses. n Reduce water and energy costs. n Regulate and standardize plumbing fixture trade. n Protect health and the environment.

The American Water Works Association estimates nationwide savings of 6.5 billion gallons per day will be achieved by the year 2025 through these standards.

33 Chapter 4

See Figure 14 for typical simple payback Flush Valve periods for 1.6 gpf toilet retrofits. (Flushometer) Toilet Flush Valve (Flushometer) Toilets Flush valve, or flushometer, toilets use water line pressure to flush waste into the sanitary sewer system. They consist of a valve and a toilet bowl fixture. Most commercial/industrial facilities use flush valve toilets, especially in higher-use areas.

For maintenance checklist, see Figure 13.

Retrofits Valve inserts are available and can reduce flush volumes by 0.5 to 1.0 gpf. Some of FIGURE 15 these devices consist of plastic orifices, Estimated Water Savings perforated with holes in a wheel and Public Facilities (gpd per toilet) spoke pattern. Others actually replace the existing valve mechanisms of a 5 gpf unit Fire Stations 28 with a 3.5 gpf valve without changing the Police Stations 20 toilet bowl fixture. Do not retrofit ultra- Libraries 76 low valves (1.6 gpf) without changing a Recreational Facilities 117 fixture bowl.

Source: Public Facilities Toilet Retrofits, A&T Technical Services, Inc., Replacement 1994, based on study of 70 public facilities in San Diego, California. Replacing inefficient units with an ultra FIGURE 16 low (1.6 gpf) flush valve mechanism and toilets will result in the maximum water Commercial/ Estimated Water Savings savings. It is important to note that both Business Sector (gpd per toilet) the low flow valves and bowls should be replaced simultaneously. A 1.6-gpf valve Wholesale 57 must be used with an appropriately Food Stores 48 designed 1.6 gpf bowl, or the unit will not Restaurants 47 perform adequately. Retail 37 Automotive 36 Pressurized tanks Multiple Use 29 Manufacturing 23 system toilets Health Care 21 The most modern and effectively de- Office 20 signed toilet currently on the market is Hotel/Motel 16 the pressurized tank toilet. These units perform very well at removing waste, but Source: The CII ULF Saving Study, 1997, California Urban Water Conservation Council. Survey of 452 organizations in California. also are more costly. These toilets use

34 Chapter 4

Making a toilet replacement project successful

Below are factors to consider when installing new ULF fixtures:

n Replace highest use toilets first – highest use toilets will provide quickest payback. n Carefully choose toilet type depending on use level and the poten- tial for misuse. n Know your sewer infrastructure. Older cast iron types with a larger diameter (4” and 6”) may have more problems transporting waste with 1.6 gallons. Substandard waste water pipe grading should be addressed before installing water efficient toilets. Make sure the building’s water pressure is adequate if switching from a gravity type to flushometer or pressurized tank toilets. Usually, 25 to 35 psi or more at the toilet is required for pressure dependant systems. n ULF toilets cannot be used as trash cans. If flushing trash is a prob- lem at the facility, employee education with the new toilet installa- tion is necessary. n Ask for references from building manager, plumbers, or other users who have installed the manufactured products. n Base decisions on the current models. Many design improvements continue to be made. n Listen to noise levels of the model you are considering. n A high cost does not automatically mean better performance. n Ask about guarantees and returns especially for future leak prob- lems. n Choose a licensed plumber or contractor. n Plan for the legal disposal of old toilets. Consult your local solid waste authority for recycling options or disposal requirements.

Use Satisfaction Some owners of early 1.6 ULF toilets reported dissatisfaction. Many improvements have been made in the 1.6 gpf toilet design to address these issues. It is important to remember that 1.6 gpf units are finely-tuned design systems that require proper use. The type of toilet should be cho- sen carefully for its level of use and application. Educating employees not to flush trash and of the importance of water efficiency will go a long way in improving user satisfaction. Actual customer satisfaction surveys conducted in Santa Rosa, California; Denver, Colorado; and New York City had a high customer satisfaction rate for customers installing ULF toilets. Less than 10 percent reported any dissatisfaction.

35 Chapter 4

water line pressure to compress air in a special sealed tank in the toilet. When flushed, the compressed air greatly increases the flush water force.

Figures 15 and 16 show examples of water Pressurized Tank Toilet savings from implemented ULF retrofit programs in both public and commercial settings.

Other options: composting toilets Where sewers or septic tanks are not available, composting and incinerating toilets are available. Before purchasing any of these toilets, make sure building inspection programs can approve such toilet systems.

Urinals The typical water consumption for urinal is two to three gpf. New federal standards require all urinals to use no more than C A S E S T U D Y 1.0 gpf. Urinals can have a flushometer valve or water tanks for both washdown Urinal Timer Adjustment and trough urinals. Waterless urinals exist that use a biodegradable liquid in place of The Asheville Civic Center has sev- water to provide flushing action. Water- eral large banks of urinals to handle less urinals are more popular in Europe. restroom traffic during large events. Sensors had been installed to continu- ously flush all urinals when the Siphon jet urinals restroom doors were open. This These common urinals are designed to system lead to excess water use. accommodate relatively high level usage. After a water audit by the WRATT The siphon jet urinal has an elevated program, a two-minute delay timer tank to provide the flushing action to was added to the sensor so the remove foreign matter such as cigarette urinals could not flush more fre- butts and gum wrappers. While these quently than every two minutes. This types of toilets are more sanitary than simple change saved almost 90 washout toilets and require little mainte- percent of urinal water use and nance, the great disadvantage is that reduced water consumption by water runs through these units constantly. 600,000 gallons per year. Washout/washdown and blowout urinals all are used in different traffic demand settings. Water efficiency options vary with each unit.

36 Chapter 4

n Check for leaks every six months. Showerhead n Check flushometer valves for leaks. For tank-style urinals, check the rubber diaphragm for leaks or wear, and replace as needed. n Use a timer. A timer can be in- stalled to stop water flow when a facility is not occupied. n Use electronic eye sensors to flush automatically.

Washout and washdown urinals Replacement options Some models can be retrofitted to use less water per flush by replacing a part in the flush valve or float levels in tanks. Make sure any retrofit will con- Behavioral modifications tinue to allow adequate removal of liquid waste. Again, bowls and flush valves need n Encourage users to take to be compatible in design use to function shorter showers. User awareness is properly. Installing new models that use important especially in institu- 1.0 gpf can achieve the maximum water tional settings. savings for urinals. n Check regularly for leaks, and institute a program to have users Special Note: Monitoring toilet usage patterns or employees inform maintenance may indicate that replacing a toilet with a less about leaks. water intensive urinal is possible. Plumbing modifications Showerheads Install flow restrictors. These washer-like Showerhead replacement or modification disks fit inside the showerhead and limit represents another water efficiency area water flow. Flow restrictors are very that is very cost effective. Most conven- inexpensive (less than $5) and easy to tional showerheads use three to seven install. Newer designs are not noisy at gpm at 60 psi water pressure. New stan- higher pressures. dards require showerheads to use no more than 2.5 gpm. These new water Temporary cut-off valves usually are efficient showerheads come in many attached to, or incorporated into, the different models and features and typi- showerheads to allow the user to tempo- cally perform very well. Water efficient rarily cutoff water while soaping, sham- showerheads also reduce energy consump- pooing, or shaving. The water can be tion for hot water generation. reactivated at the previous temperature without no need to re-adjust hot and cold water valves. Facility managers employing cutoff valve showerheads should be

37 Chapter 4

Modification Faucet aerator n Adjust flow valves to the faucet. Keep in mind this modification also can be easily changed by users. n Check regularly for leaks. faucet n Use aerators for faucet flow con- trollers on existing faucets. Aera- upper washer tors screw onto the faucet head lower washer and add air to the water flow while reducing water flow. They are available at common ratings of aerator 0.5, 0.75, and 1.0 gpm. Flow rates as low as 0.5 are adequate for hand wetting purposes in a bath room setting. Higher flow rate kitchen aerators deliver water at 2.0 to 2.5 gpm for more general washing purposes. Aerators cost warned that water temperature may be $5 to $10 installed and typically hotter upon reactivation, which could yield a payback within a few cause unexpected burns. months. n Install flow regulators. Flow Replacement options regulators can be installed in the The best water efficiency option is to hot and cold water feed lines to purchase new 2.5 gpm showerheads. The the faucet. Common flow rate products vary in price, from $3 to $48. designs include 0.5, 0.75, 1.0, and Good single-setting showerheads can be 1.5 gpm. Flow restrictors can be purchased for less than $10. The newer used where aerators cannot be code compliant showerheads have a used or where there is faucet narrower spray area and a greater mix of abuse (aerator removal is problem- air and water than conventional atic). Flow restrictors can be showerheads. Wide arrays of spray pat- installed for less than $25 and also terns are available, including adjustable yield a paybackwithin months. massage action. Fixed and flexible posi- tion models also are available. Replacement Any new faucet purchase must have a Faucets flow rate less than 2.5 gpm. Many types of Conventional faucet flow rates can range faucet and water control systems are from three to five gpm. A leaking faucet available for commercial faucets. These dripping one drip per second can waste 36 include: gallons of water a day. Federal guidelines mandate that all lavatory and kitchen n Automatic shutoff – once handle faucet and replacement aerators manufac- is released, valve shuts off. tured after January 1, 1994, consume no n Metered shutoff – once new lever more than 2.5 gpm at 80 psi. is depressed, the faucet delivers a water flow for a pre-set time

38 Chapter 4

FIGURE 17 Water Efficiency Summary: Domestic Applications1, 2, 3 Fixture Current Syle/ Ages Water Efficiency Options/ Installed Typical Comments Flow Rates Water Saving Estimates Cost ($) Payback (years)

Toilets Flushometer 1977 to Install new 1.6 gpf ULF model. $115-$300 1.5 – 6 Must change both bowl and 3.5 gpf early 1990s Saves 1.9 gpf. valve

Consider valve inserts. Save 0.5 $10-$30 0.6 –2.5 Usually not recommended by gpf OEM

Flushometer Pre- 1980s Install 3.5 gpf valve retrofit with $25-$40 0.7 – 1.7 Flushometer valves used in 4.5 gpf no change to china bowl. Saves commercial high use areas. 1.0 gpf.

Tank-type 1992 and Best available option. NA NA Ultra-low flush (<1.6 gpf) gravity later exist for special eviro- 1.6 gpf sensitive cases.

Tank-type 1977 to Install 1.6 gpf gravity toilet or $115-$300 1.5 - 6 Displacement devices/dams gravity - 3.5 mid- 1990 other 1.6 gpf models. Saves 1.9 not typically recommended gpf gpf. for 3.5 gpf units.

Consider early closing flapper. $20 0.7-1.5 Adjustable for quality Saves from 0.5 to 1.0 gpf. performance

Tank-type - Pre-1980 Install 1.6 gravity flush or other $115-$300 0.7-4.5 Consider pressurized tanks gravity 5-7 gpf devices 1.6 gpf models. systems for high use areas.

Consider dams, displacement $20 0.4-0.9 Do not use bricks. devices, or early closure flapper. Saves 0.75-2 gpf. Urinals4 Flushometer Install repair valves to 1.0 or $20-$40 1.0 –3.5 For non-pooling styles 1.6 gpf 0.5 gpf for non-pooling styles. Saves 0.6-1.1 gpf.

Flushometer Replace urinal fixture and $100-$250 1.8 - 8.0 3.0 gpf retrofit valves to 1.0 gpf. Saves 2.0 gpf.

Showerhead5 2.5 gpm Post mid- Currently Best Option – lower NA NA Rated at 60 psi pressure. 1990s flow showerhead available for special condition (down to 1.5 gpm).

3-5 gpm Post 1980 Install 2.5 gpm showerhead. <$20 0.5-2.5 Appropriate pressure needed

5-8 gpm Pre-1980 Install 2.5 gpm showerhead. <$20 0.25-0.5 Appropriate pressure devises needed.

Kitchen 3-7 gpm Pre 1980 Install aerators to reduce flow $5-$10 0.4-3.5 Faucets6 devises to 2.5 gpm. No less than 2.5 gpm for kitchen applications. Lavatory 3 - 7 gpm Pre 1980 Install aerators to reduce flow to $5-$10 0.05-0.7 Faucets7 devises 1.0 gpm or as little as 0.5 gpm. 0.5 gpm aerators suitable for bathroom wetting services.

1 Based on an average water and sewer rate in North Carolina of $3.97 per 1,000 gallons. 2 Payback estimated for one shift operations. Divide payback period by two and three for two and three shift operations, respectively. 3 Cost estimates are based on approximate installation cost using internal maintenance. Actual cost and payback periods may vary. Options based on widely available equipment believed not to reduce service quality or reliability. 4 Urinal savings based on two uses per day per male employee. 5 Showerhead savings base on two eight-minute showers per work day. 6 Kitchen faucet savings based on three minutes of use per day. 7 Lavatory faucet use based on 10 seconds of use per restroom visit.

39 Chapter 4

period (e.g. five to 20 seconds), Water spigots then automatically shuts off. Self-closing commercial valves are avail- able for water spigots, like those installed Infrared and in public areas. Shut-off cycles from four Ultrasonic Sensors to 25 seconds typically are available. “Electric eye” sensors are available for a number of plumbing applications includ- Pressure Reducing Valves ing lavatory faucets, urinals, and toilets. Facilities should consider using a pressure- These devices deliver a metered flow only regulating valve when water line pressure when the fixture is in use. For faucets, is higher than 50 to 60 psi. Lowering both the flow rate and activation time excessively high-line pressure helps reduce can be adjusted. The “no-touch” activa- the formation of leaks and will lower tion also is helpful to prevent the spread water flows from spigots, hoses, faucets, of disease and useful for users with dis- and water feed lines. A pressure reduction abilities. Sensored faucets, too, need to be of 15 psi from 80 to 65 psi will reduce checked for leaks and clogged flow water flow by about 10 percent without controllerss because of any water impuri- sacraficing water service. A reduction ties. An infrared sensored faucet or from 80 to 50 psi will correspond to about urinal/toilet controls can be purchased a 25 percent water use reduction in light for about $200. commercial settings.

40 Chapter 4

Cooling and Heating

Cooling tower

Boiler

Background over the wet decking to cause evapora- tion. Fans pull air through the tower in a The use of cooling towers represents the counterflow, crossflow, or parallel flow to largest reuse of water in industrial and the falling water in the tower. Fore most commercial applications. Cooling towers efficient cooling, the air and water must offer the means to remove heat from air mix as completely as possible. conditioning systems and from a wide variety of industrial processes that gener- ate excess heat. While all cooling towers Evaporation continually reuse water, they still can Cooling occurs in a tower by the mecha- consume 20 to 30 percent of a facility’s nisms of evaporative cooling and the total water use. Optimizing operation and exchange of sensible heat. The loss of maintenance of cooling tower systems can heat by evaporation (approximately 1,000 offer facility managers significant savings Btu per pound of water) lowers the in water consumption. remaining water temperature. The smaller amount of cooling also occurs when the remaining water transfers heat Cooling Tower Design (sensible heat) to the air. Warm water is recirculated continuously from a heat source, such as an air condi- The rate of evaporation is about 1.2 tioning system or process equipment, to percent of the rate of flow of the recircu- the cooling tower (See Figure 18.) In most lating water passing through the tower for cooling tower systems, warm water (or every 10 F decrease in water temperature water to be cooled) is pumped to the top achieved by the tower. The decrease in of the tower where it is sprayed or dripped water temperature will vary with the through internal fill materials called wet ambient dew point temperature (DPT). decking. The wet decking creates a large The lower the dew point, the greater the

surface area for a uniform thin film of temperature difference ( T)∇ between water to be established throughout the water flowing in and out of the tower. tower. Air is blown through falling water Another rule of thumb for estimating the

41 Cooling Tower Evaporation l l

l System Schematic . &ift l

\ 15 ’ Warmer water

Process heat source, heat exhanger, or condenser

A

\ Wet decking fill t Make-up water I Coolerwater / ..___, --...r -..- - oncentrated mineral salt:; LL / . - Recirculating Da.-.? Treatment chemicals

rate of evaporation from a cooling tower water can be maintained to reduce is as follows: evaporation equals three mineral scalebuild-up and other contami- gallons per minute (gpm) per 100 “tons” nants in the tower, cooling condensers, of cooling load placed in the tower. The and process heat exchangers.Thermal term “ton,” when used to describecooling efficiency, proper operation, and life of tower capacity,is equal to 12,000 British the cooling tower are related directly to thermal units (Btu) per hour of heat the quality of the recirculating water in removed by the tower. When the dew the tower. point temperature is low, the tower air induction fans can be slowed by using a Water quality in the tower is dependent motor speedcontrol or merely cycled on on makeup water quality, water treat- and off, saving both energyand water ment, and blowdown rate. Optimization evaporation losses. of blowdown, in conjunction with proper water treatment, represents the greatest opportunity for water efficiency improve- ment. Blowdown can be controlled Blowdown is a term for water that is manually or automatically by valves removed from the recirculating cooling actuated by timers or conductivity meters. water to reduce contaminant buildup in the tower water. As evaporation occurs, water contaminants, such as dissolved solids, build up in the water. By removing Drift is a loss of water from the cooling blowdown and adding fresh makeup tower in the form of mist carried out of water, the dissolved solids level in the the tower by an air draft. A typical rate of Chapter 4

Figure 18

Cooling Tower Evaporation System Schematic Drift

Water flow

Air flow

Make-up water Wet decking fill C Water sump and concentrated mineral salts

Treatment Blowdown chemicals

rate of evaporation from a cooling tower water can be maintained to reduce is as follows: evaporation equals three mineral scale build-up and other contami- gallons per minute (gpm) per 100 “tons” nants in the tower, cooling condensers, of cooling load placed in the tower. The and process heat exchangers. Thermal term “ton,” when used to describe cooling efficiency, proper operation, and life of tower capacity, is equal to 12,000 British the cooling tower are related directly to thermal units (Btu) per hour of heat the quality of the recirculating water in removed by the tower. When the dew the tower. point temperature is low, the tower air induction fans can be slowed by using a Water quality in the tower is dependent motor speed control or merely cycled on on makeup water quality, water treat- and off, saving both energy and water ment, and blowdown rate. Optimization evaporation losses. of blowdown, in conjunction with proper water treatment, represents the greatest Blowdown opportunity for water efficiency improve- ment. Blowdown can be controlled Blowdown is a term for water that is manually or automatically by valves removed from the recirculating cooling actuated by timers or conductivity meters. water to reduce contaminant buildup in the tower water. As evaporation occurs, water contaminants, such as dissolved Drift losses solids, build up in the water. By removing Drift is a loss of water from the cooling blowdown and adding fresh makeup tower in the form of mist carried out of water, the dissolved solids level in the the tower by an air draft. A typical rate of

42 drift is 0.05 to 0.2 percent of the total circulation rate. Reduction in drift through baffles or drift eliminators will conserve water, retain water treatment chemicals in the system, and improve operating efficiency.

F- ii IL .I .1~ Fee-s =,,I6 :; tly” L in, ., ., ,j:(.a: ‘

Cooling Tower Water Balance

Drift, “D” Evaporation, “E”

b Make-up water, “M” Cool water to process Blowdown, “B” v

Water Balance : M = E + B+ D

Concentration Ratio: CR = M Quality / B Quality Chapter 4 drift is 0.05 to 0.2 percent of the total FIGURE 19 circulation rate. Reduction in drift through baffles or drift eliminators will CONCENTRATION RATIO conserve water, retain water treatment chemicals in the system, and improve operating efficiency. total dissolved solid (TDS) of make-up water TDS of blowdown Make-up water Makeup water is water added to the OR cooling towers to replace evaporative, µ blowdown, and drift losses. The amount specific conductance ( mhos) of make-up of make-up water added directly affects µmhos of blowdown the quality of water in the systems. The relationship between blowdown water quality and make-up water quality can be expressed as a “concentration ratio” or a Water balance “cycle of concentration.” This ratio is A simple water balance on a cooling shown in Figure 19. tower system can be determined if three of the four following parameters are The most efficient use occurs when the known: make-up, evaporation, drift, and concentration ratio increases and blowdown. (See figure 20 for a description of blowdown decreases. the cooling tower water balance.) FIGURE 20

Cooling Tower Water Balance

Drift Evaporation, "E"

W Cooling Tower

Make-up water, "M" Co Blowdown, "B"

Water Balance : M = E + B+

Concentration Ratio: CR = M Quality /

43 Chapter 4

W A T E R E F F I C I E N C Y O P T I O N S for cooling towers

FIGURE 21 Percent of Make-up Water Saved

New Concentration Ratio (CRf) ) i 22.533.545678910 1.5 33% 44% 50% 53% 56% 58% 60% 61% 62% 63% 64% 2 ——- 17% 25% 30% 33% 38% 40% 42% 43% 44% 45% 2.5 ——- ——- 10% 16% 20% 25% 28% 30% 31% 33% 34% 3 ——- ——- ——- 7% 11% 17% 20% 22% 24% 25% 26% 3.5 ——- ——- ——- ——- 5% 11% 14% 17% 18% 20% 21% 4 ——- ——- ——- ——- ——- 6% 10% 13% 14% 16% 17% 5 ——- ——- ——- ——- ——- ——- 4% 7% 9% 10% 11% Initial Concentration Ratio (Cr 6 ——- ——- ——- ——- ——- ——- ——- 3% 5% 6% 7%

Blowdown Optimization solved solids (TDS) of blowdown water be 2,000 ppm or greater for a new large Water consumption of cooling towers can cooling facility whose total cooling capac- be reduced significantly by minimizing blowdown in coordination with an

integrated operation and maintenance CRi - CRf program. Blowdown is minimized when V = Mi X (CR )(CR -1) the concentration ratio increases. Typical i f concentration ratios are 2-to-3, and V = volume of water conserved generally can be increased up to six or M = initial make-up water volume more. i (before modification) CR = concentration ratio before Some states have passed laws governing i increasing cycle the quality level in a cooling tower as an CR = concentration ratio after attempt to promote efficient cooling f increasing cycles tower water use. For example, the State of Arizona requires that the total dis-

44 Chapter 4 ity is greater than 250 tons or three conductivity, hardness, and microorgan- million Btu. ism levels. The use and sensitivity of a cooling system also will control how much The volume of water saved by increasing blowdown can be reduced. Scale, corro- the cycles of concentration can be deter- sion, fouling, and microbial growth are mined by this equation: four critical parameters that must be For example, increasing concentration controlled in cooling towers. Minimum ratio from two to six will save 40 percent blowdown rates must be determined in of the initial make-up water volume. tandem with the optimum water treat- Table 21 allows users to easily estimate ment program for the cooling tower. potential water savings. Controlling Blowdown The maximum concentration ratio at To better control the blowdown and which a cooling tower can still properly concentration ratio, facilities can install operate will depend on the feedwater submeters on the make-up water feed line quality, such as pH, TDS, alkalinity,

Practical guidance for working with a service contractor

n Work closely with your chemical vendor or contracted service provider to reduce blowdown. Because reduc- ing blowdown also reduces chemical purchasing require- ments, facility personnel must keenly set up perfor- mance-based service contracts.

n Require vendors to commit to a predetermined mini- mum level of water efficiency. Have them provide an estimate of projected annual water and chemical con- sumption and costs.

n Tell your vendor that water efficiency is a priority, and ask about alternative treatment programs that will help reduce blowdown.

When purchasing chemicals for treating cooling tower water, have the chemical vendor explain the purpose and action of each chemical. Your vendor should provide a written report of each service call. Be sure the vendor explains the meaning of each analysis performed, as well as the test results.

45 Chapter 4

and the blowdown line. Submetering allows operators to carefully control water use. In some areas, evaporative water loss, H2SO4 as determined by submetering and water balances, can be subtracted from local sewer charges. Submeters can be installed on most cooling towers for less than tower water to help $1,000. control scale Blowdown can be conducted manually or buildup. When automatically. Recirculating water systems properly applied, are blown down when the conductivity of sulfuric acid will lower the water’s pH and the water reaches a preset level. Typically, help convert the calcium bicarbonate this is done in a batch process, blowing scale to a more soluble calcium sulfate down sizable water volumes. A better form. In locations in Southern California approach is to use a conductivity control- and Phoenix, facilities are able to operate ler to continuously bleed and refill water cooling towers at a concentration ratio of in the system. Continuous systems main- 5-to-6 using sulfuric acid treatment. tain water quality at a more consistent level without wide fluctuations in TDS. Important precautions need to be taken when using sulfuric acid treatment. Cooling Tower Water Because sulfuric acid is an aggressive acid that will corrode metal, it must be care- Treatment fully dosed into the system and must be Almost all well-managed cooling towers used in conjunction with an appropriate use a water treatment program. The goal corrosion inhibitor. Workers handling of a water treatment program is to sulfuric acid must exercise caution to maintain a clean heat transfer surface prevent contact with eyes or skin. All while minimizing water consumption and personnel should receive training on meeting discharge limits. Critical water proper handling, management, and chemistry parameters that require review accident response for sulfuric acid used at and control include pH, alkalinity, con- the facility. ductivity, hardness, microbial growth, biocides, and corrosion inhibitors. Side Stream Filtration In cooling towers that use makeup water Depending of the quality of the make-up with high suspended solids, or in cases water, treatment programs may include where airborne contaminants such as dust corrosion and scaling inhibitors, such as can enter cooling tower water, side stream organophosphate types, along with filtration can be used to reduce solids biological fouling inhibitors. These build-up in the system. Typically five to 20 chemicals normally are fed into the percent of the circulating flow can be system by automatic feeders on timers or filtered using a rapid sand filter or a actuated by conductivity meters. Auto- cartridge filter system. matic chemical feeding tends to decrease chemical dosing requirements. Rapid sand filters can remove solids as small as 15 microns in diameter while Sulfuric “Acid” Treatment cartridges are effective to remove solids to Sulfuric acid can be used in a cooling 10 microns or less. Neither of these filters

46 Chapter 4 are very effective at removing dissolved solids, but can remove mobile mineral scale precipitants and other solid contami- nants in the water. The advantages of side C A S E S T U D Y stream filtration systems are a modest reduction in scale formation and fouling, which allows longer periods between Bayer Corp. in Clayton, North major maintenance. Carolina, substantially reduced city water consumption for cooling Ozone towers by reusing the “reject” Ozone can be a very effective agent to stream from their reverse osmosis treat nuisance organics in the cooling (RO) water treatment process. By water. Ozone treatment also is reported reusing the RO “reject” water to to control the scale by forming mineral replace cooling tower evaporative oxides that will precipitate out to the losses, Bayer is saving 10 million water in the form of sludge. This sludge gallons of city water per year.

FIGURE 22

Summary of Cooling Tower Water Efficiency and Treatment Options Option Advantages Disadvantages Low capital costs None Operation improvements Low operating costs to control blowdown and Low maintenance chemical additions requirements

Low capital cost Potential safety hazard Sulfuric acid treatment Low operating cost Potential for corrosion damage if Increased concentration overdosed ratio

Low possibility of fouling Moderately high capital cost Side stream filtration Improve operation Limit effectiveness on dissolved efficiency solids Additional maintenance

Increased concentration High capital investment Ozonation ratio Complex system Reduced chemical Possible health issue requirements

Reduced scale Novel technology Magnet System Reduced or eleminated Controversial performance claims chemical usage

Reduces overall facility Increased fouling potential water consumption Low concentration ratios required Reuse of water within the Possible need for additional water facility pretreatment

47 Chapter 4

collects on the cooling tower basin or in a Alternative Sources of separate tank. Ozone treatment consists Make-up Water of an air compressor, an ozone generator, Some facilities may have an opportunity a diffuser or contactor, and a control to reuse water from another process for system. The initial capital costs of such cooling make-up water. Water reuse from systems are high but have been shown to reverse osmosis reject water, wastewater provide payback in 18 months. from a once through cooling process, or from other clean wastewater streams in Magnets the plant are examples. In some cases, Some vendors offer special water treating treated effluent can be used as cooling magnets that alter the surface charge of tower make-up if the concentration ratio suspended particles in cooling tower is maintained conservatively low. Simi- water. The particles help disrupt and larly, blowdown streams may be suitable break loose deposits on surfaces in the for use as process water in some applica- cooling tower system. The particles settle tions in a low velocity area of the cooling tower  such as sumps where they can be It has been reported that municipal mechanically removed. Suppliers of these wastewater effluent from tertiary treat- magnetic treatment systems claim that ment may be suitably used as make-up magnets will remove scale without con- water. In these reuse applications, reports ventional chemicals. Also, a similar novel of phosphate scale formation was prob- treatment technology, called an electro- lematic where water softening pretreat- static field generator, can be investigated ment was not also employed. and validated. Eliminate Once-Through Cooling Many facilities use “once-through” water to cool small heat generating equipment. Once-through cooling is a very wasteful C A S E S T U D Y practice because water is used only one time before being sewered. Typical Eliminating Once-Through Cooling equipment that can be using once- through cooling includes: vacuum pumps, A small medical equipment manufac- air compressors, condensers, hydraulic turer in Arden, North Carolina, was equipment, rectifiers, degreasers, X-ray using a continuous tap water flow of processors, welders, and sometimes even 12 gpm to cool a 20-horsepower air conditioners. Some areas of the vacuum pump. After a water effi- country prohibit the use of once-through ciency audit, the company installed a cooling practice. Option to eliminate chiller water recirculating system. The once-through cooling are typically very company is now saving 6.6 million cost effective. They include: gallons of water per year, an estimated $30,500 annual savings in water and n Connect equipment to a recircu- sewer costs. lating cooling system. Installation of a chiller or cooling tower is usually an economical alternative.

48 Chapter 4

Sometimes excess cooling capacity cooled ice making machine. already exists within the plant that n Reuse the once-through cooling can be utilized. water for other facility water n Consider replacing water-cooled requirements such as cooling equipment with air-cooled equip- tower make-up, rinsing, washing, ment. One example is switching and landscaping. from a water-cooled to an air-

49 ~g#=qqJ,g-&j__lbll*I in ,,& ~gv$!~ggs measuresin their daily operations. The advancementsof landscapedesign and Irrigation and the care of landscapesis an maintenance technologies have made the important target for water efficiency. The upkeep of healthy, efficient landscapes demand for water in landscapinghas simple and cost effective. With the causedmany areasof the-country to adopt assistanceof extension agenciesand measuresto regulate the distribution of consulting services,facility managerscan water supply. Some municipalities in develop optimum managementmethod- North Carolina, such as Cary and ologies to meet landscapingneeds and Salisbury, have implemented landscaping water reduction goals. ordinances, rate structures, and wastewa- ter reuse systemsto deal with water shortagesand drought. As a growing trend nationwide, municipal conservation programs are heightening the awareness Xeriscaping is an approach that combines of design, installation, and maintenance selecting, placing, and maintaining plants standards for commercial landscapes. for optimum water management.The practice of xeriscapingbegan as a way to Facility managersare becoming more lessenthe effects of water shortages,while aware of the need for water efficiency maintaining the aesthetic and functional Chapter 4

W A T E R E F F I C I E N C Y I N L A N D S C A P I N G

Trends in Awareness measures in their daily operations. The advancements of landscape design and Irrigation and the care of landscapes is an maintenance technologies have made the important target for water efficiency. The upkeep of healthy, efficient landscapes demand for water in landscaping has simple and cost effective. With the caused many areas of the country to adopt assistance of extension agencies and measures to regulate the distribution of consulting services, facility managers can water supply. Some municipalities in develop optimum management method- North Carolina, such as Cary and ologies to meet landscaping needs and Salisbury, have implemented landscaping water reduction goals. ordinances, rate structures, and wastewa- ter reuse systems to deal with water shortages and drought. As a growing Xeriscaping for Water trend nationwide, municipal conservation Efficiency programs are heightening the awareness Xeriscaping is an approach that combines of design, installation, and maintenance selecting, placing, and maintaining plants standards for commercial landscapes. for optimum water management. The practice of xeriscaping began as a way to Facility managers are becoming more lessen the effects of water shortages, while aware of the need for water efficiency maintaining the aesthetic and functional

50 Chapter 4 qualities of a site. Xeriscape systems can FIGURE 23 reduce total water demand by as much as Municipal Building 50 percent or more. There are seven basic Example of Xeriscaping at a Municipal Facility principles to xeriscaping: Low Water Shrub Zone 1 Planning and Design

Moderate Water A comprehensive design plan is the initial Turf Zone step to a water-efficient landscape. A well- thought and researched design will minimize cost and attain a proper strategy for plant and sprinker placement. These Low Water factors should be considered: Turf Zone

Very Low Water n Site conditions such as drainage, Shrub Zone soil type, sun exposure/shade, aesthetic preferences, existing Very Low Water plantings, slope/grade, and water availability are all crucial elements of an efficient plan. n Intended use of the site must be carefully considered, including subsequent stormwater pollution. recreation, habitat, and traffic. n Consider using porous materials n Trees, shrubs, and grass all require such as porous concrete or perme- different amounts of water. Plants able paving methods. should be placed in groups accord- n Consider grading and directing ing to their respective water surface run-off and rainfall gutters needs, called hydrozones. This way to landscaped areas as opposed to an irrigation system can be de- drainageways that exit the prop- signed to properly match the erty. needs of the plants, soils and weather conditions. 2 Soil Analysis and Improvement n A proper irrigation design should have a base schedule that includes n Soil testing will help determine sprinkler run times and weekly soil quality and absorptive capac- frequency for every month. This ity. Choose plants based on these base schedule is used as a starting findings. Most soils require some point for an irrigation manager. adjustment of the pH (acidity or n Incorporate high water demand- alkalinity). Contact your county ing plants at the bottom of slopes. cooperative extension offices for n Incorporate the use of existing more information about how to trees, plants, and wildlife areas to conduct soil testing. The North help add value to the site. Carolina Department of Agricul- n Consider creating shade areas, ture (NCDA) provides free soil which can be 20 degrees cooler testing and improvement recom- than non-shaded areas. mendations. n Minimize the use of impervious n Organic matter such as compost, surfaces to reduce runoff and mulch, or manure increases the

51 Chapter 4

and two inches of water per week. n Plant grass only where it will provide optimal functional and aesthetic benefits. n Avoid very small turf areas under 10 feet wide. n Proper watering of turf (less frequent and deeper versus frequent and light watering) will promote deep root development, which will make the turf more drought tolerant. water holding capacity of soil and n Where growing climates permit, can help improve water distribu- consider warm season grasses such tion. as bermuda and zoysia that n When improving the soil of a require 50-75 percent less water given area, it is important to treat than cool season tall fescues. a large area around the planting n Studies have shown that mowing to allow ample space for root turf at alternating heights can systems. save up to 30 percent in watering n Do not allow heavy construction requirements. Cutting grass short equipment to compact soil around reduces water demand and existing trees or other sensitive cutting it higher leads to deeper natural areas. root development and more drought tolerance. 3 Proper Plant Selection n Whenever possible, plant alterna- tive groundcovers that require less water, or consider the use of n The selection of drought-tolerant, patios and decks, further reducing native species to a given area will water demand. greatly reduce maintenance costs and can improve the aesthetic presentation of a site. 5 Efficient Irrigation n Consider plants’ water demand, pest tolerance, soil nutrient, and n The proper design, installation, drainage requirements. and maintenance of both the n Native species are adapted to work irrigation system and the land- together in similar soils and scape accomplish efficient irriga- benefit each other’s growth by tion. No amount of good mainte- forming symbiotic relationships. nance can overcome the ineffi- ciencies of poor design. 4 Practical Turf Areas n Effective irrigation incorporates watering plants deeply, infre- quently, and slowly. Saturating n Turf grasses have the largest water the soil deep enough to assist consumption patterns of any plant roots in growth is crucial; water- group. Typically, turf in North ing a higher number of times in a Carolina requires between one time period will restrict growth.

52 Chapter 4

Extra irrigation will be required 6 Use Mulches during establishment for most Mulches are various organic materials, plantings. such as pine/oak bark, pine straw, aged n Automatic systems are a cost- wood chips, and compost mixtures that effective way of ensuring that are placed around the root zone of a proper watering occurs, although plant. it is important to adjust the system regularly for weather changes and n The use of mulches around plant growth. planting is highly effective in n Trees, shrubs, and groundcovers retaining soil moisture and reduc- are watered most effectively ing the need for watering and through drip emitter pipes and maintenance. spray emitters that target the root n Three to five inches of mulch zone of each plant. reduces the level of evaporation n Uniformity of the water being from the soil, insulates root applied by the irrigation system is systems from heat, and limits the the key ingredient in irrigation germination of weeds around beds efficiency. Sprinkler uniformity is and flora. affected by the operating pressure, n Fine textured mulches help retain the nozzle used, and the sprinkler more moisture than coarse spacing. mulches. n By observing the water consump- tion rates of plants throughout a growing season (called evapotrans- 7 Proper Maintenance piration, or ET rates), one can get The most crucial element in sustaining an idea of the needs of the site as water efficiency in any landscape site is seasons change. ensuring that a regular maintenance n Rain and moisture sensors add to the efficiency of a system, keeping in mind that maintenance always is necessary to ensure proper and C A S E S T U D Y dependable functions. n Overspray that covers concrete or The City of Santa Monica, California, other impervious areas can was one of the first cities to require negatively impact an area by the use of xeriscaping for all land- contributing to runoff, pavement scapes installed in new commercial damage, and pollution of water and industrial development. resources adjacent to a site. n The excessive or improper use of Requirements included the use of low irrigation systems can severely water plant materials, 20 percent hamper the nutritive ability of a maximum allowable turf area, low site’s soil content. Nutrients can volume methods for irrigation (i.e. leach out of the soil and move auto controllers, moisture sensors, across a site to contaminate and proper device placement, ongoing groundwater sources. maintenance programs, and restricting the use of decorative water fountains and lakes).

53 Chapter 4

FIGURE 24 and native landscaping techniques to minimize the environmental effects from runoff, pesticides, fertilizer, water con- sumption, and other effects caused by maintenance practices. Ecologically balanced landscapes not only conserve resources and money but they physically improve property, reduce long term maintenance costs, and create land conscious landscapes. Benefits of ecologi- cally-based, water-conserving landscapes include:

n Reduced off-site water consump- Root development (left) when tion. watering deeper and less frequently. n Lower HVAC requirements. n Provision for pedestrian move- ment and habitat needs. n Maintained nutrients on site. n schedule is met. Attention to the land- Lower energy use and pollution n scape and irrigation system at regular time Reduced water pumping and intervals will lower the cost of mainte- water treatment. n nance, and increase the effectiveness of Lessened runoff of stormwater water for landscaping. and irrigation water. n Lower maintenance and labor n Mow grass at a proper height. costs. n Never mow grass to a height less Increased quality of landscape and than one-third its original height. surrounding habitat. n Regular aeration of clay soils will improve water holding capabilities Water Efficient Options for and prevent runoff. Existing Landscapes n Use irrigation schedules that attain a deep and healthy root A wide range of water efficiency options system. are available for existing landscapes. n Keep nutrient levels balanced Facility managers should read the follow- throughout the seasons. ing list as well as review the previous n Inspect and adjust the sprinker explanation of the xeriscaping principle emitters, filters, valves, and for performance improvements. Addi- controllers for proper operation tionally, professional help can be obtained once a month. by contacting the Irrigation Association for a list of certified irrigation designers, certified landscape water auditors and Benefits of Well-Planned certified irrigation contractors in North Xeriscaping Carolina. Planning and development of functional landscapes should incorporate not only xeriscaping principles, but also use natural

54 Chapter 4

When to Water Amount of Water Plants Require n Water in the early morning or late evening to maximize absorption n Use ET data to help determine a and minimize evaporation. These plant’s water needs. techniques can save as much as 30 n Water deeply once or twice a week percent of your watering demand. instead of lightly every day. (See n Water when wind is less than 10 Figure 24.) miles per hour. n To prevent runoff or deep percola- n Water only when plant groups are tion below the roots, never apply showing signs of drought stress. water faster than the soil can take n If there has been significant rain it in or more than the soil can to replace the water used (evapo- hold. (See Maximum Sprinkler Run transpiration, ET rate), do not Time figure.) water. A rain sensor attached to n Assess the characteristics of a site the irrigation timer will accom- through a water audit. Audits plish this automatically.

Average Weekly Run Times for North Carolina Minutes Per Week Water Cool season turf Warm season turf Shrubs required (inches/week) Spray Rotor Spray Rotor Spray Rotor

March 0.77” 42 141 36 123 28 94 April 1.19” 65 219 56 189 43 146 May 1.47” 80 270 69 234 53 180 June 1.61” 88 296 76 256 59 197 July 1.66” 91 305 78 264 60 203 August 1.57” 86 288 74 250 57 192 September 1.12” 61 206 53 178 41 137 October 0.74” 40 136 35 118 27 91

To Use: 1. Identify the type of plant material the valve is watering. 2. Determine the type of sprinkler heads on that valve. 3. Locate the weekly runtime for the current month and divide the number of minutes by the number of days the valve will operate in one week. 4. Enter that daily run time on the controller. 5. Repeat for each valve on the controller. 6. Set the controller to come on the same number of days in a week as you divided by.

These average run times are meant as a starting point to build an irrigation schedule. Every landscape has different soil types, micro-climates, and plant types. Each system also will operate with different pressures, sprinkler spacings, and brands of sprinklerheads. All these differences will require that these times be adjusted to meet the specific conditions of every zone valve.

55 Chapter 4

n Check for leaking valves. Maximum Sprinkler n Inspect low-volume emitters for plugs. Run Time n Inspect sprinklers for clogged Minutes Per Application nozzles. n Adjust sprinklers to water plant Sprinkler type material and not sidewalks or Soil type Spray Rotor roads. n Adjust the operating time Sand 15 to 20 45 to 60 (runtimes) of the sprinklers to Loam 10 to 15 30 to 45 match the seasonal or monthly Clay 7 to 10 20 to 30 requirements. n Take soil samples to look for compaction or thatch buildup. evaluate the specific water needs and conditions of an existing site. n Consider that every square foot of Irrigation System watershed hardscape can shed more than 25 gallons of irrigation Operations water every year. n Consider adding a rain shutoff Where to Water device, rainfall sensors, or a soil tensiometer to your automatic irrigation control system. n Plants should be watered at their n Consider alternative sources for roots, not on their leaves or irrigation water, including the use trunk. of wells as opposed to city water, n Make sure automatic irrigation water reuse options from foun- systems such as drip and sprinklers tains, non-contact cooling water, are adjusted to reach plant roots. or even treated graywater. n Select and maintain sprinkler n Use electronic controllers with heads to avoid watering sidewalks precise timing, multiple irrigation and pavement. zones, multiple cycles, and at- tached rain shut-off devices. n System Maintenance Incorporate separate irrigation Considerations

n Replace sprinklers with like sprinklers. Spray heads should not operate on the same value with rotors. n Ensure spray heads are aligned with grade. n Replace worn spray nozzles. n Regulate pressure properly for system demands.

56 Chapter 4

zones for all irrigated plant situations like broken heads or pipes, hydrozones, and use separate valve malfunctions, or many other water irrigation zones for turf areas. saving sensors. n Use dedicated water meters for landscaping water use. A central control system does not relieve n Use drip or other low volume the water manager from monitoring and irrigation wherever possible. adjusting the equipment. It allows them n Have a catchment, or DU (distri- to quickly adjust multiple controllers to bution uniformity), test performed the monthly or daily changes in condi- on-site to determine how evenly tions that affect the water needs of the water is applied when sprinklers plants. This typically results in the preven- are in use. tion of over-watering. Water Efficient Technologies PC Software There are software programs that have Automatic Irrigation Timer been developed to assist the designer and A simple-to-operate automatic timer or water manager in the analysis of the controller can be installed on an existing efficiency of an existing or newly designed manual irrigation system. The controller irrigation system. Two of the primary automatically will operate the sprinklers programs were developed by the Center on the proper day of the week for the for Irrigation Technology at California correct amount of run time. This will State University, Fresno. The program meet the plant’s water needs as well as used to generate graphic representations apply the water in off-peak night or early of sprinkler efficiencies is called Hyper- morning hours. More elaborate control- SPACE. The software that analyzes the lers offer extra flexibility to manage larger costs versus the benefits of improving sites with many different hydrozones and irrigation efficiencies is called SPACE site conditions. Any controller can use a Irrigation Survey. Many Certified Water rain soil moisture sensor to prevent the Auditors and Certified Irrigation Design- sprinklers from operating when natural ers use this software programs extensively. precipitation has met the plant’s water needs. Sensors Centralized Irrigation Controllers There are two basic types of sensors used in water management. The soil moisture To manage many irrigation controllers, sensor measures the moisture levels in the spread out among many sites, a central- ized control system will save labor costs as well as increase water efficiencies. A typical central irrigation control system C A S E S T U D Y utilizes a personal computer (PC) to create, adjust, and save irrigation sched- ules for multiple controllers at various Aurora, Colorado, eliminated more locations. The PC then communicates to than one billion gallons of water the controllers by radio, hardwire, tele- needs by the construction of a waste- phone, or a combination of two or more water reuse system that uses indus- methods. A PC central system can also trial wastewater for irrigation. monitor and react to different alarm

57 Chapter 4

soil and the rain sensor measures the level, stop the irrigation. When the amount of effective rainfall. Both are conditions dry out, the rain sensor allows designed to be added to any automatic the controller to resume normal opera- irrigation controller. They both prevent tion. They do not affect the program- the controller from activating the valves if ming of the controller. there is either enough moisture of rain- fall. Water Efficient Plants A major factor of water efficient land- Soil moisture sensors detect moisture in a scapes is the selection of plants. Plants’ number of different ways. The specific watering needs are divided by hydrozones. soil conditions and landscape layout will The use of drought tolerant and native determine which type is best suited for plants not only minimizes runoff con- the application. When properly main- cerns, but also can strategically make the tained, soil moisture sensors can reduce most use of rainfall patterns. In addition water use by as much as 40 percent. to the lists of drought tolerant plants (See Rain sensors have the single largest next tow pages.), the North Carolina impact on water savings in an automatic Cooperative Extension Services can irrigation system of any equipment that provide further information and assis- can be added. Rainfall sensors measure tance for selecting water efficient plants. the amount of rainfall and, at a preset

58 Chapter 4

Common Name Botanical Name y B Lacebark elm Ulmus parvifolia Japanese zelkova Zelkova serrata Tulip poplar Liriodendron tulipfera Sycamore Platanus occidentalis Laurel Oak Quercus laurifolia C Live Oak Quercus virginiana Pin Oak Quercus palustris White Oak Quercus alba Crepe Myrtle Lagerstroemia indica Hollies Ilex spp. Chaste tree Vitex agnus-castus T R E S Sweet gum Liquidambar styraciflua

e Common Name Botanical Name d

Chinese photinia Photinia serrulata Elaeagnus Elaeagnus d Firethorn Pyracantha coccinea (pyracantha) Japanese privet Ligustrum japonicum Junipers Juniperus spp. Yaupon holly Ilex vomitoria Mahonia Mahonia spp. Nandina Nandina domestica Chinese holly Ilex cornuta Strawberry bush Euonymus americana Forsythia Forsythia intermedia Barberry Berberis spp. Quince Chaenomeles japonica Viburnum Viburnum spp. Euonymus Euonymus spp. Spirea Spirea spp. Glossy abelia Abelia grandiflora

S H R U B Jasmine Jasminum spp.

59 Chapter 4

COVERS/VINES Common Name Botanical Name Mondograss Ohpiopogon japonicus Liriope Liriope spp. Junipers Juniperus spp. Thrift Phlox subulata English Ivy Hedera helix Clematis Clematis spp. Trumpet Honey Lonicera sempervirens Suckle Wisteria Westeria spp. Wintercreeper Euonymusfortunei

GROUND Periwinkle Vinca spp.

PERENNIALS Common Name Botanical Name Gazania Gazania rigens Annual Vinca Catharathus roseus & Annual phlox Phlox drummondii Baby’s breath Gypsophila spp. Black-eyed Susan Rudbeckia spp. Coreopsis Coreopsis spp. Cape marigold Dimorphotheca sinuata Cornflower Centaurea cyanus Cosmos Cosmos spp. Globe amaranth Gomphrena globosa Moss rose Portulaca grandiflora Straw flower Helichrysum bacteatum Verbena Verbena spp. Butterfly weed Asclepias tuberosa Gaillardia Gaillardia x grandiflora Goldenrod Solidago hybrids Liatris Liatris spp. Purple coneflower Echineacea prurpurea Sedum Sedum spp. ANNUALS Stokes’ aster Stokesia cyanea Chapter 4

K I T C H E N & F O O D P R E P A R A T I O N

Although commonly overlooked, there terns. The main types of water-using are many ways to reduce water usage in equipment found in kitchens are dish- the kitchen. Traditionally, saving water washers, faucets, ice-making machines, has not been a major consideration of and garbage disposal use. Improved commercial food preparers. Many estab- technology has eliminated many of the lishments cite the lack of money or employees as reasons for not using water conservation methods. Case histories have shown that water efficiency pro- grams are cost-effective, and most initial C A S E S T U D Y costs are retrieved within a two-year period. Participation in water efficiency A study of 605 industrial water effi- programs shows that there is a concern ciency programs by the Metropolitan for efficient water. These programs are Water District of California estimated supported by local communities. that facilities cut kitchen/cafeteria water use by 32 percent, yielding a Inefficient uses of water in kitchen saving of nearly 100,000 CCF of operations come mainly from two areas: water per year. equipment design and behavioral pat-

61 Chart1

Typical Water Use of Commercial Dishwashers

flightconv

clineconv type

singledoor

ucounter

max. 0 0.5 1 1.5 2 2.5 3 min. gallons/rack

Page 1 Chapter 4

FIGURE 25

Typical Water Use of Commercial Dishwashers

flightconv

clineconv type

singledoor

ucounter

0 0.5 1 1.5 2 2.5 gallons/rack

water issues associated with equipment, as necessitate stronger mechanical action more rigid standards have been created to and more concentrated detergents for curtail excessive water use. Water audits of cleaning. commercial facilities have shown that 60 percent of identified water savings comes Types of Dishwashing from simply installing faucet aerators in all kitchen sink outlets. An effective part Machines of water savings in kitchens is attributed There are four main types of dishwashing to behavioral patterns in facilities. Aware- machines: undercounter, door, conveyor, ness programs, education, training, and and flight. A wide array of models and job performance measures can influence accessories are available for each category. proper behavioral patterns of staff. Requirements for machine size can be calculated by estimating the amount of Dishwashers traffic that will be served in the food service area. Energy guidelines and water All dishwashing machines employ wash, consumption levels for dishwashers are rinse, and sanitizing cycles. The sanitizing becoming stricter, and many manufactur- cycle typically is the chemical reduction of ers offer new water-saving models. Figure microorganisms to safe levels on any food x illustrates typical water use ranges for utensil. The time taken for a dishwasher each type of dishwasher normalized on a to complete a cycle is a combination of “per rack” basis. Most importantly, note mechanical action, water temperature, the wide range of water use in each and chemical action. Most dishwashers dishwashing category. (See Figure 25.) use between 2.0 and 7.0 gpm for a com- Using an appropriately sized, water plete cycle of cleaning and sanitation. Hot efficient model will save a significant water use varies with the pressure of amount of water. supply lines, operation speed of the machine, and dish table layout. All these variables are intrinsically linked Undercounter and any adjustments affect each compo- Smallest of commercial dishwashers, nent. For example, rapid washing cycles undercounter dishwashers are best suited

62 Chapter 4 for small establishments of about 60 people. They commonly are used in nursing homes, churches, small food Types of dishwashing machines service areas, office buildings, and for glass washing in taverns and bars. The undercounter machines are similar to n undercounter residential dishwashers in that the door n door-type opens downward with rack(s) rolling out n C-line conveyor, or rack onto the lowered door for access. n flight type A revolving wash arm handles the wash and rinse cycles, with a small holding tank being automatically drained after each cycle. An automatic timer controls cycle C-line Conveyor, Rack length. Undercounter machines come in C-line, or rack conveyor, machines use a both hot water and chemical sanitizing motor-driven conveyor belt to move the models, with optional booster heaters for rack-loaded dishes through a large tank the latter. As can be seen in Figure 25, with separate wash and rinse compart- undercounter machines use the most ments. Most widely-used in hotels, large water per rack of all commercial dish- restaurants, hospitals, schools, and univer- washers. This illustrates the need to wash sities, these machines are well suited for only full racks when the machine is in service of 200 or more people, accommo- use. dating most heavy food service opera- tions. Door-type Manufactured to service 50-200 people, C-line machines come in varying sizes, door type machines are the most widely with available additions such as pre-wash used of commercial dishwashing ma- units, side-loading trays, condensers, and chines. Door machines are used in blower-dryers. A single tank holds the schools, hospitals, churches, restaurants, water and detergent at a regulated tem- catering businesses, fast-food establish- perature. The wash solution is pumped ments, and as glass and utensil units in through multiple spray arms (revolving or larger operations. These box-shaped stationary) that run constantly once the machines have singular or multiple doors machine is operational, regardless the that slide vertically for loading and presence of a dish rack. The rack is then unloading. Door type machines are sent through the rinse compartment, available in high temperature and chemi- where it is sprayed with the 180 F water cal sanitizing models. These “dump and by spray nozzles above and below the rack. rinse” machines have a single tank for C-line machines with multiple tanks differ water and detergent, which are circulated in that some use stationary versus rotating in measured volumes and temperatures. spray arms. The racks then are sent into a Two revolving spray arms (one above and pump-driven rinse tank that rinses the one below the dish rack) distribute wash dishes heavily. This process usually uses solutions evenly over the dishes. Some recycled water from the final rinse. All door-type machines now have the ability rack conveyor machines have a timer to recycle rinse water to be used again in a control for the speed of the conveyor to wash cycle. assure proper wash and rinse times.

63 Chapter 4

Water efficient measures, such as the loading a dishwasher. installation of an electric eye sensor (that n Instruct staff to quickly report keeps the conveyor from running when leaks and troubleshoot. there are no dishes on the racks) have n Only run rack machines if they started to make rack conveyors more are full. energy- and cost-effective. Some efficient n Try to fill each rack to maximum conveyors can reduce final rinse consump- capacity. tion from 300 gph to 130 gph. The use of energy efficient boosters and low flow Mechanical Modifications pumps can reduce energy and water consumption levels by 50 percent. n Recycle final rinse water for washing. Flight type n Keep flow rates as close as possible Similar in that they use a conveyor belt to to manufacturer specifications. move dishware, flight type machines do n Install “electric eye sensors” to not have racks. Rather, dishes are loaded allow water flow only when dishes directly onto the belt. Flight type dish- are present. washers provide high volume washing n Install door switches for conve- capability needed only in the largest nient on/off access. institutional, commercial, and industrial n Check voltage of booster heater to facilities. Variations in possible machine make sure it fits the machine. additions include power scrapers, power n Uses “steam doors” to prevent loss wash, power rinse, final rinse, and blower- of water due to evaporation. dryers. n Install low temperature machines that rely on chemical sanitizing Water efficient strategies for these ma- over high water temperature. chines include the recirculation of final n Check volume of service and rinse water, electric eye sensors, extra-wide estimate facility needs  a better conveyors, and low-energy built-in booster option may be a larger machine heaters. These additions have amounted that has a lower water flow rate to water savings as much as 47 percent, per rack. while maintaining loads of more than 14,000 dishes per hour. Kitchen Faucets and Water Efficient Practices for Pre-rinse Sprayers Faucets can waste large amounts of water, Dishwashers as they are the most heavily used water The volume of consumption in dishwash- source in kitchens. Conventional faucets, ers can be reduced by a variety of prac- with typical flow rates of 2.5 to 4.0 gpm, tices, all of which target awareness of can waste as much as 40 gallons of water a equipment and operation needs. day when not fully closed. Since 1994, water efficiency standards have been Behavioral Modifications federally mandated, requiring that all post 1994 manufactured faucets consume a n Educate staff about the benefits of maximum of 2.5 gpm @ 80psi. But many water efficiency and the impor- facilities have older fixtures with rubber tance of hand scraping before gaskets that wear and deform because of

64 Chapter 4 high amounts of hot water use. By simply installing a brass gasket and an automatic shut-off nozzle, a facility could save as C A S E S T U D Y much as 21,000 gallons of water per year. There have been many adjustments and technology advancements in faucet design By installing a foot-actuated faucet, one as a variety of low-flow faucet types are food service facility reduced its monthly manufactured. Foot-activated kitchen water usage by 3,700 gallons. This faucets will reduce water use while provid- translated to annual savings of nearly ing additional convenience. Faucets used $700. in kitchens will be primarily the conven- tional type or pre-rinse pressure sprayers. There are a variety of modifications that can be employed for all types.

Water Efficiency Options for dishes, and cleaning. They are designed with automatic shut-off valves at the hose Kitchen Faucets head to supply water only when needed. There are water efficient spray valves n Adjust flow valve to reduce water offered that supply from 1.6-2.65 gpm @ flow. 80psi. These types of sprayers are designed n Check for leaks and worn gaskets. to meet the demands of food service n Install a flow restrictor to limit operations. maximum flow rate to 2.5 gpm or less. Ice Making Machines n Install a 2.5 gpm faucet aerator, Ice machines have many commercial uses, maximizing flow efficiency by from restaurants to lodges, and can use increasing airflow to the stream. significant amounts of water depending n Consider infrared or ultrasonic on the type of machine and the desired sensors that activate water flow type of ice. Ice machines are composed of only in the presence of hands or the following components: a condensing some other object. unit used for cooling, an evaporator n Install pedal operated faucet surface for ice formation, an ice har- controllers to ensure valves are vester, an ice storage container, and, in closed when not in use. some models, a dispenser. The type of n Educate staff to look for leaks and condenser an ice machine uses will have broken faucets in their area. the largest effect on water use. Two types n Do not leave faucets on to thaw of condensers are available: air-cooled and vegetables and other frozen foods. water-cooled. Water-cooled machines use n Post water conservation literature 10 times as much water as air-cooled and reminders to staff around machines and water rarely is recirculated. work areas. (See Figure 26.) In comparing water- and air-cooled compressors, the compressor Pre-rinse Sprayers horsepower at design conditions is invari- Pre-rinse sprayers are used for rinsing ably higher with air-cooled machining. cooking utensils, pots, pans, soaking However, operating costs frequently compare favorably during a full year. The

65 Water Use for Commercial Ice-Cube Machines

Water-cooled

Max Min

Condenser Type Air-cooled

0 50 100 150 200 250 300 350 Gallons/100 Pounds of Ice Chapter 4

FIGURE 26

Water Use for Commercial Ice-Cube Machin

Water-cooled

Air-cooled Condenser Type

0 50 100 150 200 250 300 Gallons/100 Pounds of Ice

Water-cooled machines use 10 times as much water as air-cooled machines and water rarely is recirculated.

desired quality and visual clarity of ice also that employ a mesh screen to collect food will influence water consumption. Ice waste for proper waste treatment. An- quality, machine cleaning, and water other option is to install strainers in sinks, efficiency all need to be balanced for leaving the food matter in the sink for optimum operation. disposal in trash receptacles or composting units. Garbage Disposals Studies show that garbage disposals can waste a significant amount of water. It is recommended that their use be mini- mized or eliminated from kitchen opera- tions. Many facilities use strainers or traps

66 Chapter 4

C L E A N I N G A N D R I N S I N G A P P L I C A T I O N S

Most industrial and commercial busi- actively solicited and involved in water nesses have a variety of cleaning and reduction efforts, behavior, and equip- rinsing applications that can consume ment modifications will successfully large volumes of water. Water efficiency reduce water consumption. techniques presented here address general water uses for process change-overs, Dry Cleanup equipment clean-out, parts rinsing, tanks Dry clean-up means using brooms, rinsing, line flushing, floor cleaning, and brushes, vacuums, squeegees, scrapers, other applications. Because this section is and other utensils to clean material before generic in nature, the water efficiency water is used. By collecting the majority of concepts presented will need to be indi- wastes, residues, or contaminants in a dry vidualized for specific business needs and form, large volumes of water and waste- any regulatory cleanliness standards. (Also water can be eliminated. The bulk of solid see sections on metal finishing, textiles, and materials can be more efficiently removed food processing for more specific water effi- in dry form before water is introduced for ciency applications.) secondary washing.

Education: Examples of Dry Clean-up Practices First and Foremost Employees must be aware of the need for n Sweeping floors instead of hosing water efficiency. Many cleaning processes with water. can be made significantly more efficient n Vacuuming or sweeping dry by simple measures. If employees are material spills such as salt or dyes

67 Chapter 4

C A S E S T U D Y Dry Cleanup

The Equity Group in Reidsville, North Carolina, instituted a comprehensive program to reduce water use and wastewater pollutant loading in their food processing operation. Employees were trained to remove all dry waste from floor and equipment for cleaning. Because of dry clean-up practices, much of the waste food residuals can have a secondary use, such as for animal food. Dry-cleanup, improved employee awareness, and other opera- tion modifications saved 1.25 million gallons per month and reduced organic pollutant loading to wastewater by 50 percent. ing wastewater system. n Saves energy for processes that use hot water. n Reduces hydraulic capacity de- instead of using water. mands on any wastewater treat- n Use squeegees and scrapers first to ment systems. remove residual from machines n Better enables the reuse, recy- such as ink sludge from machine cling, or composting, of “dry” troughs between color change- collected materials. overs. n Vacuuming or sweeping particu- Eliminate/Reduce Floor late emissions (dust) instead of hosing with water. Washing Where Feasible

Use rubber squeegees to collect food n Many floor surfaces (i.e. ware- processing residuals from the floor before houses, offices, automotive ga- hosing with water. Use “pigs” to purge rages, non-critical processing areas, residual from pipes before flushing with facility support operations, etc.) do water. not need to be washed with water. n If necessary, use dry absorbents, Benefits of Dry Clean-up and sweep or vacuum these areas. n Find and eliminate the source of n Saves water and reduces wastewa- spills and leaks that may be the ter. sole reason why water washdowns n Reduces water, wastewater, and are needed. surcharge costs. n Spot mop if necessary. n Reduces pollutant loading enter- n Use floor mats, “clean-zones,” and

68 Chapter 4

other means to reduce the track- n Use conductivity controllers to ing of waste and dirt residual regulate rinse water flow rates. throughout a facility. (See Chapter 5.) n Use spray washing/rinsing tech- Use Efficient Spray niques for tank cleaning versus refilling/dropping tank Washing/Rinse washwater. Many improvements can be made to the water delivery system for washing and rinsing. Proper selection, control, use, and maintenance are essential. Consider these suggestions: C A S E S T U D Y

n Do not use a hose as a broom. High Pressure Washers This practice is a waste of valuable labor, water, and energy. n Use efficient spray nozzles with Sparta Foods, in St. Paul, Minnesota, automatic shut-offs on the end of replaced garden hoses with high- hoses. Garden hose nozzles are pressure washers to clean equipment not very efficient. that processes flour products. The n Consider high-pressure washers to new high-pressure washers cost $200 clean more quickly and efficiently. each. Equipment now is cleaned n Consider pressurized air-assisted quicker and more efficiently using half spray nozzles to provide more the water. The washers save 217,000 cleaning force with less water. gallons of water per year, and payback n Use low-flow “fogging” nozzles to was less than three months. rinse parts efficiently. n Use flow restrictors in water lines that supply hoses and pressure FIGURE 27 washers. n Use timers to shut off process Examples of Process Water Reuse water rinses when process is shut

down. Cleaning Process n Turn off running water when not Before/After Reuse in use. Tap Water n Ensure stationary spray nozzles are Feed

Process Equipment aimed properly. Before Requiring Cleaning or n Review nozzle spray patterns for Flushing Water to Sewer optimum application. Fan, cone, hollow cone, air atomizing, fine Tap Water S Feed spray, and fogging are a few Water Feed with Reuse S Quality Sensor: R examples of nozzle spray patterns. conductivity, pH, NTU, etc n Replace worn spray nozzle heads, After Process Equipment Requiring Cleaning or Wash Water Flushing Water Out Recirculation or that lead to poor spray patterns Reclamation and excessive water consumption. Tank Water To Sewer/ n Use counter current washing Treatment techniques. (See Chapter 5.)

69 Chapter 4

Cleaning Water Reuse Tremendous opportunity exists to reuse C A S E S T U D Y cleaning and rinsing water in-process. Instead of using water only once, water Process Water Reuse can be pumped or drained to a recircula- tion tank for reuse. Depending on water Jackson Paper in Sylva, North Carolina, quality requirements for the particular manufactures corrugated cardboard stage of reuse, water simply may be medium from 100 percent recycled recirculated or require basic treatment feedstock. An on-site wastewater such as solid settling, oil skimming, and/ facility allows 100,000 gallons of waste- or filtration using cartridge, bag, disk, water per day to be reused on-site. indexing fabric, or sand filtration. (See Treated mill water is reused for paper- Figure 27.) Water quality control standards making, boiler scrubber make-up need to be carefully established for each water, and sludge press showers in the point of reuse. For high water quality wastewater treatment area. No waste- demands, more advanced water reclama- water is discharged from the facility. tion techniques exists, such as ultrafiltra- The intensive water reuse modifica- tion, nanofiltration (or reverse osmosis), tions save an estimated $92,000 per carbon filtration, and ion exchange. year. In-process water reuse can allow the user to salvage a valuable product that pres- ently is being discharged as wastewater, such as cleaning chemicals in washing solutions or valuable metals in rinsing C A S E S T U D Y solutions.

In-plant Water Reuse Also consider staged cleaning techniques where the first and second pass cleaning Outboard Marine Corporation, in water is saved for reuse or product recla- Andrews, North Carolina, manufac- mation. tures gear assemblies for outboard motors. Annually, the company gener- ated 85,000 gallons of wastewater Water Reuse Rules from water soluble coolant, compres- With several areas in North Carolina sor blowdown, mop water, and parts approaching limits on the reasonable cleaning. The facility installed a availability of high-quality fresh water nanofiltration unit to treat the oily as well as limits on the capacity of wastewater and reclaim water for streams to assimilate the wastewater reuse in coolant formulation and mop they receive, wastewater reuse rules water. Now 56,000 gallons of water is have been revised to encourage the reclaimed and $24,000 in wastewater reuse of industrial, domestic, and disposal costs are saved each year. municipal wastewater. On June 1, 1996, revised rules went into effect that regulate water reuse within North Carolina.

70 Chapter 4

Industrial effluents can be directly reused without a non-discharge permit in these specific reuse situations: n Industrial process water within C A S E S T U D Y the facility that originated the Cleaning Solution Reuse effluent. n Cooling tower make-up water. T.S. Designs, a screen printer in n Fire-fighting or extinguishing Burlington, North Carolina, would water. clean printing screens using strong Other uses of reclaimed industrial oxidizing solution in manual wiping effluents are allowed but are contin- application. To reduce chemical gent upon (1) a demonstration by the consumption and save water, T.S. facility that the quality of the water is Designs installed a 43-gallon reclama- such that employee health and safety tion tank to continuously filter and are protected and (2) a notification to circulate the aqueous cleaning solu- employees that nonpotable reclaimed tion past the printing screen sus- water is being used. Examples of such pended in a tank. A similar reuse other uses include: system was used for a stain and haze n Irrigation of property. removing wash step. The reuse n Dust control. process allows cleaning solution to n Decorative ponds. be used continuously for one month. n Vehicle washing With the reuse system, less concen- n Street cleaning. trated and safer solutions could be employed. The reuse system saves All valves, piping, storage facilities, $5,200 per year in chemical, water, outlets, and other means of distribu- and sewer costs. tion of reclaimed water must be tagged or labeled to inform employees that the water is not intended for drinking. In addition, no cross- and as industrial process or cooling connection can occur between the water. reclaimed water and potable water Other reuse scenarios for either systems. Where potable water is used industrial or municipal wastewater to supplement the reclaimed water may include urinal and toilet flushing system, an air gap must separate the and sprinkler systems or other fire potable and reclaimed water. The protection in industrial, commercial supplemental system is subject to or residential applications. The rules approval by the potable water sup- explicitly prohibit the use of reclaimed plier. water for irrigation of direct food To provide a greater protection from chain crops; make up for swimming pathogens, reuse limitations are more pools, spas, and hot tubs; and raw stringent for domestic and municipal potable water supply. effluents than for industrial effluents. The most likely reuse situations for The specific rule language can be accessed domestic wastewater are to irrigate and downloaded from the Division of golf courses, parks, and other areas Water Quality’s web site. The rules are

71 Chapter 4

located in Subchapter 2H.0200 - Non- Cleaning Chemical Changes Discharge Rules. For questions about a Changes in the type, temperature, and wastewater reuse application or a copy of concentration for cleaning solutions can the regulation, contact Donald Safrit, save water. P.E., Assistant Chief for Technical Sup- port, Division of Water Quality, P.O. Box Operational Controls and 29535, Raleigh, NC 27626-0535, (919) Maintenance 733-5083, ext. 519. Overflow controls should be in place for filling tanks and vessels. Other Improvements to the Cleaning Process Sub-Metering Water Use Teflon Surface Coatings Some businesses restrict water flow to an Tanks, vats, pipeline, other equipment entire processing area and force water surfaces can be coated with a Teflon non- operators to find the optimum ratio level stick surface. This allows for easier clean- for individual activities. Sub-metering and ing during process line changeovers and monitoring allows excessive water con- clean-up. sumption and leaks to be quickly detected and corrected.

Vehicle Washwater Recycling Many commercial water recycle systems are available for fleet maintenance and vehicle cleaning. With a recycle water C A S E S T U D Y permit from the proper authority, facili- ties can install a washwater recycle system Integrated Water Conservation for vehicle cleaning.

Washwater recycling systems provide Campbell Soup Company in Maxton, several advantages over typical waste- North Carolina, instituted a corporate water disposal: wide integrated pollution prevention program. For water efficiency mea- 1. These systems allow for simple sures, Campbell soup used dry-clean- cleanup of contaminants from up procedures for floors and equip- spills or system failures by ment, installed process water flow preventing entry to the meters, and eliminated water trans- sanitary sewer or septic system. port (fluming) of scrap. A continuous 2. These systems reduce costs for maintenance/housekeeping schedule water use and disposal. was implemented instead of the 3. Many of the systems are pre- previous once-a-day practice. These engineered, have a proven water efficiency techniques have saved track record, and can be $125,000 annually in operating costs. submitted for permit issuance The program also improved solids from previously approved collection and recycling. plans and specifications.

72 Chapter 4

Typical washwater recycling systems Although such systems can be nearly consist of a sedimentation basin for grit/ closed-loop, except for occasional solids sand removal, an oil/water separator, removal and filter backwash wastewater, filtration, and a disinfection unit to occasionally water must be changed due to prevent biological growth. Basin/sump buildup of dissolved solids (salts). Washing compartments are used to settle grit, practices and discharges to the recycle sand, and other solids and also used to system must be closely controlled, as they skim any floating oils. Water then is will not handle shock loads. Maintenance filtered, typically using a multimedia filter to the treatment/recycle equipment also that removes solids in the water larger is very important. Pre-engineered units than five to 20 microns in diameter. The for single wash bays cost approximately filtered water is oxidized/sanitized to $20,000. The regional staff for the North reduce organics and meet any health/ Carolina Division of Water Quality can safety standards for non-potable water provide additional details about permits reuse. Water then is stored and pumped for a recycling system. back to the washing bay for reuse.

73 Chapter 5

Industry Specific Processes

Textiles 5 Food Metal Finishing

T E X T I L E S *

FIGURE 28 Water Use in Textile Processing Water Use Water Use Water Use Processing Minimum, gal/lb Median, gal/lb Maximum, gal/ Subcategory of production of production lb of production

Wool 13.3 34.1 78.9 Woven 0.6 13.6 60.9 Knit 2.4 10.0 45.2 Carpet 1.0 5.6 19.5 Stock/Yarn 0.4 12.0 66.9 Nonwoven 0.3 4.8 9.9 Felted Fabrics 4.0 25.5 111.8

* Excerpts from “Best Management Practices for Pollution Prevention in the Textile Industry,” EPA, 1996.

74 Chapter 5

Water Consumption Subcategory in Textiles Textile operations vary greatly in water consumption. Figure 28 summarizes the Water is used extensively throughout water consumption of various types of textile processing operations. Almost all operations. Wool and felted fabrics dyes, specialty chemicals, and finishing processes are more water intensive than chemicals are applied to textile substrates other processing subcategories such as from water baths. In addition, most fabric wovens, knits, stock, and carpet. preparation steps, including desizing, scouring, bleaching, and mercerizing, use Water use can vary widely between similar aqueous systems. operations as well. For example, knit mills average 10 gallons of water per pound of The amount of water used varies widely in production, yet water use ranges from a the industry, depending on the specific low of 2.5 gallons to a high of 45.2 processes operated at the mill, the equip- gallons. These data serve as a good ment used, and the prevailing manage- benchmark for determining whether ment philosophy concerning water use. water use in a particular mill is excessive. Reducing water consumption in textile processing is important for furthering pollution prevention efforts, in part Unit Process because excess water use dilutes pollutants Water consumption varies greatly among and adds to the effluent load. unit processes, as indicated in Figure 29. Certain dyeing processes and print after- Mills that currently use excessive quanti- washing are among the more intensive ties of water can achieve large gains from unit processes. Within the dye category, pollution prevention. A reduction in certain unit processes are particularly low water use of 10 to 30 percent can be in water consumption (e.g., pad-batch). accomplished by taking fairly simple measures. A walk-through audit can Machine Type uncover water waste in the form of: Different types of processing machinery use different amounts of water, particu- n Hoses left running. larly in relation to the bath ratio in n Broken or missing valves. dyeing processes (the ratio of the mass of n Excessive water use in washing water in an exhaust dyebath to the mass operations. of fabric). Washing fabric consumes n Leaks from pipes, joints, valves, greater quantities of water than dyeing. and pumps. Water consumption of a batch processing n Cooling water or wash boxes left machine depends on its bath ratio and running when machinery is shut also on mechanical factors such as agita- down. tion, mixing, bath and fabric turnover n Defective toilets and water cool- rate (called contact), turbulence and other ers. mechanical considerations, as well as physical flow characteristics involved in In addition, many less obvious causes of washing operations. These factors all water waste exist. These causes are pre- affect washing efficiency. sented below by subcategory, unit process, and machine type. In general, heating, wash, and dyebaths

73 Chapter 5

FIGURE 29 Water Consumption by Unit Process Processing Water Consumption, Subcategory gal/lb of production

Yarn & fabric forming Nil Slashing 0.06 to 0.94 Preparation Singeing Nil Desizing 0.3 to 2.4 Scouring 2.3 to 5.1 Continuous bleaching 0.3 to 14.9 Mercerizing 0.12 Dyeing Beam 20 Beck 28 Jet 24 Jig 12 Paddle 35 Skein 30 Stock 20 Pad-batch 2 Package 22 Continuous bleaching 20 Indigo Dyeing 1 to 6 Printing 3 Print afterwashing 13.2 Finishing Chemical 0.6 Mechanical Nil

76 Chapter 5 constitutes the major FIGURE 30 portion of energy consumed in dyeing. Therefore, low Water Consumption bath-ratio dyeing equipment not only conserves water but for a Typical Bleach Range also saves energy, in addi- Stage Water, gph Percent, % tion to reducing steam use and air pollution from boilers. Low-bath-ratio Saturators 550 5 dyeing machines conserve Steamer and J Boxes 150 1.4 chemicals as well as water Washers and also achieve higher Desize 3,700 33.5 fixation efficiency. But the washing efficiency of some Scour 3,100 28.1 types of low-bath-ratio Bleach 3,100 28.1 dyeing machines, such as Dry cans 450 4.1 jigs, is inherently poor; Total 11,050 100 therefore, a correlation between bath ratio and total water use is not always exact. A report on water consumption for a typical continuous bleach range found Process Water that consumption was more than 11,000 Conservation gallons per hour, or 270,000 million gallons per day. (See Figure 30.) Washing Washing stages accounted for 9,900 gallons per Washing and rinsing operations are two hour, or 90 percent of the total. The of the most common operations in textile application of the following simple, low- manufacturing that have significant technology methods of water conserva- potential for pollution prevention. Many tion reduced water use: processes involve washing and rinsing stages, and optimizing wash processes can n Properly regulating flows: 300 conserve significant amounts of water. In gallons per hour savings. some cases, careful auditing and imple- n Counterflowing bleach to scour: mentation of controls can achieve waste- 3,000 gallons per hour savings. water reductions of up to 70 percent. The n Counterflowing scour to desize: washing and rinsing stages of preparation 3,000 gallons per hour savings. typically require more water than the other stages (e.g., bleaching, dyeing). The total water savings without process Several typical washing and rinsing modification was 150,000 million gallons processes include: per day, or 55 percent of water use. A process modification such as a combined n Drop and fill batch washing. one-stage bleach and scour also would save n Overflow batch washing. 6,200 gallons of water per hour, or an n Continuous washing (countercur- additional 150,000 million gallons per rent, horizontal, or inclined day, along with energy savings. washers).

77 Chapter 5

FIGURE 31 Water Use in Batch Washing Process Water Use, % Change from Description Bath Ratio gal/lbs Standard

1 Standard - 3 step drop/fill 1:8 1.62 --- 2 Reduced bath - seven step drop/fill 1:5 1.26 -22.2 3 Continuous overflow 1:8 2.38 46.9 4 Continuous overflow - reduced bath 1:5 1.49 -8 5 Three-step drop/fill, reuse bath 2 1:8 1.19 -26.5 6 Three-step, reuse baths 2 and 3 1:8 0.75 -53.7

Drop-Fill Versus The capital cost of setting up such a reuse system typically is less than $50,000 and Overflow Washing generates estimated savings of $95,000 In the drop/fill method of batch washing, annually. In many cases, reducing waste- spent wash water is drained and the water also reduces the need for expensive machine is refilled with a fresh wash bath. waste treatment systems. The fabric or other substrate in the machine retains much of the previous Reusing Wash Water bath, perhaps as much as 350 percent Many strategies can be applied for reusing owg. This percentage can be reduced by wash water. Three of the most common mechanical means (e.g., extraction, strategies are countercurrent washing, blowdown). Comparison of several reducing carryover, and reusing wash methods of washing after bleaching shows water for cleaning purposes. the benefits of countercurrent wash methods, see Figure 31. Methods five and six, which implement countercurrent Countercurrent Washing washing, produce savings of 26 and 53 The countercurrent washing method is percent compared with the standard relatively straightforward and inexpensive drop/fill method. These results are based to use in multistage washing processes. on comparisons of washing processes that Basically, the least contaminated water would produce the same degree of reduc- from the final wash is reused for the next- tion of fabric impurities using computer to-last wash and so on until the water models. reaches the first wash stage, after which it is discharged. This technique is useful for Countercurrent washing processes require washing after continuous dyeing, printing, the addition of holding tanks and pumps. desizing, scouring, or bleaching.

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An important variant of the countercur- squeeze rolls or vacuum extractors typi- rent principle is “horizontal” or “inclined” cally extract water between steps. Equip- washers. Horizontal or inclined washing is ment employing vacuum technology to more efficient because of the inherent reduce dragout and carryover of chemical countercurrent nature of water flow solutions with cloth, stock, or yarn is used within the process. The mechanical to increase washing efficiency in multi- construction of an inclined or horizontal stage washing operations. countercurrent washer has to be much better than a traditional vertical washer, In one case history, a processor installed however. vacuum slots after each wash box in an existing multistage continuous washing Sloppy roll settings, weak or undersized line and was able to reduce the number of rolls, unevenness, bends, bows, biases, boxes from eight to three . Wash boxes bearing play, or other misalignments with built-in vacuum extractors are within the machine are much more available for purchase, as well as washers important in a horizontal or inclined for prints that combine successive spray washer because the weight of water and vacuum slots without any bath for the pressing down on the fabric can cause it fabric to pass through. Because the fabric to sag, balloon, or stretch. If properly is never submerged, bleeding, marking constructed and maintained, horizontal off, and staining of grounds is minimized, or inclined washers can produce high and water use decreases. quality fabrics while saving money and water. Another washer configuration with internal recycling capabilities is the Reducing Carryover vertical counterflow washer, which sprays Because the purpose of washing is to recirculated water onto the fabric and reduce the amount of impurities in the uses rollers to squeeze waste through the substrate, as much water as possible must fabric into a sump, here it is filtered and be removed between sequential washing recirculated. The filter is unique, consist- steps in multistage washing operations. ing of continuous loops of polyester fabric Water containing contaminants that is that rotate continuously and are cleaned not removed is “carried over” into the of filtrate at one end with a spray of clean next step, contributing to washing ineffi- water. This construction allows for maxi- ciency. mum removal of suspended solids from water before discharge or reuse in an- Proper draining in batch drop/fill wash- other process. High-efficiency washing ing and proper extraction between steps with low water use results. Energy use in the continuous washing process are decreases greatly because less water must important. Often, 350 percent owg is be heated. carried over in typical drop/fill proce- dures. This amount can be reduced in Reuse for Cleaning Purposes some batch machines (e.g., yarn package In many types of operations, washwater dyeing, stock dyeing) by using compressed can be reused for cleaning purposes. In air or vacuum blowdown between wash- printing, cleanup activities can be per- ing steps. formed with used washwater, including :

In continuous washing operations, n Backgray blanket washing.

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n Screen and squeegee cleaning. Inspection of the written procedures n Color shop cleanup. showed that the fill step simply said “fill.” n Equipment and facility cleaning. The wash step simply said “wash.” With- out training and without a specific operat- A typical preparation department may ing procedure, operators were left to also reuse wash water as follows: determine water use on their own. This case may seem extreme, but even the best n Reuse scour rinses for desizing. mills, which have well-documented n Reuse mercerizer washwater for production procedures, often do not have scouring. documented cleaning procedures. Clean- n Reuse bleach washwater for ing operations that contribute large scouring. amounts of pollution to the total waste n Reuse water-jet loom washwater stream include machine cleaning, screen for desizing. and squeegee cleaning, and drum washing. n Recycle kier drains to saturator. Engineering Controls Work Practices Every mill should have moveable water Workers can greatly influence water use. meters that can be installed on individual Sloppy chemical handling and poor machines to document water use and housekeeping can result in excessive evaluate improvements. In practice, mills cleanup. Poor scheduling and mix plan- rarely measure water use but rely on ning also can require excessive cleanup manufacturers’ claims concerning equip- and lead to unnecessary cleaning of ment and water use. The manufacturers’ equipment like machines and mix tanks. estimates are useful starting points for Leaks and spills should be reported and evaluating water consumption, but the repaired promptly. Equipment mainte- actual performance of equipment de- nance, especially maintenance of washing pends on the chemical system used and equipment, is essential. Inappropriate the substrate. Therefore, water use is work practices waste significant amounts situation-specific and should be measured of water; and good procedures and on-site for accurate results. The water training are important. When operations meters should be regularly maintained are controlled manually, an operations and calibrated. audit checklist is helpful for operator reference, training, and retraining. Other important engineering controls, some of which have been discussed in In one case history, a knitting mill experi- other sections of this chapter, include: enced excessive water use on beck dyeing machines. A study of operating practices n Flow control on washers. revealed that each operator was filling the n Flow control on cooling water (use machines to a different level. Some minimum necessary). operators filled the becks to a depth of 16 n Countercurrent washing. inches, others as much as 24 inches. Also, n High extraction to reduce dragout. the amount of water used for washing n Recycle and reuse. varied. Some operators used an overflow n Detection and repair of leaks. procedure, and others used drop/fill or n Detection and repair of defective “half baths” (repeatedly draining half of toilets and water coolers. the bath, then refilling it).

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Machinery should be inspected and water intake system with no adverse improved where possible to facilitate effects on production. In some cases, cleaning and to reduce susceptibility to specific types of wastewater can be re- fouling. Bath ratios sometimes can be cycled within a process or department. reduced by using displacers that result in Examples are dyebath reuse, bleach bath lower chemical requirements for pH reuse, final rinse reuse as a loading bath control as well as lower water use. for the next lot, washwater reuse, counter- current washing, and reuse for other Process Changes purposes. Pad-Batch Dyeing In pad-batch dyeing, prepared fabric is Bleach Bath Reuse padded with a solution of fiber reactive Cotton and cotton blend preparation dyestuff and alkali, then stored (or (e.g., desizing, scouring, bleaching) are batched) on rolls or in boxes and covered performed using continuous or batch with plastic film to prevent evaporation of processes and usually are the largest water water or absorption of carbon dioxide consumers in a mill. Continuous processes from the air. The fabric then is batched are much easier to adapt to wastewater for two to 12 hours. Washing can be done recycling/reuse because the wastestream is on whatever equipment is available in the continuous, shows fairly constant charac- mill. teristics, and usually is easy to segregate from other waste streams. Pad-batch dyeing offers several significant Waste-stream reuse in a typical bleach unit advantages, primarily cost and waste for polyester/cotton and 100 percent reduction, simplicity, and speed. Produc- cotton fabrics would include: tion of between 75 and 150 yards per minute, depending on the construction n Recycling J-box and kier drain and weight of the goods involved, is wastewater to saturators. common. Also, pad-batch dyeing is n Using countercurrent washing. flexible compared with a continuous n Recycling continuous scour range. Either wovens or knits can be dyed washwater to batch scouring. in many constructions. Frequent changes n Recycling washerwater to backgray of shade present no problems because blanket washing. reactives remain water soluble, making n Recycling washerwater to screen cleanup easy. This method of dyeing is and squeegee cleaning. useful when versatility is required. Water n Recycling washerwater to color use typically decreases from 17 gallons per shop cleanup. pound to 1.5 gallons per pound, a reduc- n Recycling washerwater to equip- tion of more than 90 percent. ment and facility cleaning. n Reusing scour rinses for desizing. n Reusing mercerizer washwater for Processing Bath Reuse scouring. Water from many processes can be renovated for reuse by a variety of meth- Preparation chemicals (including optical ods. Several research efforts are under- brighteners and tints), however, must be way. In a few operations, up to 50 percent selected in such a way that reuse does not of the treated wastewater is recycled create quality problems such as spotting. directly back from the effluent to the raw-

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Batch scouring and bleaching are less easy processors because of their flexibility and to adapt to recycling of waste streams ability to conserve energy, water, and because streams occur intermittently, chemicals. They also have complete built- drains generally go into pits and are not in countercurrent capabilities. These units easily segregated, and batch preparation are being promoted for use in steps frequently are combined. With afterwashing fiber reactive and other appropriate holding tanks, however, types of dyes (e.g., after pad-batch dyeing) bleach bath reuse can be practiced in a in addition to use as continuous knit similar manner to dyebath reuse, and preparation ranges. several pieces of equipment are now available that have the necessary holding Final Rinse Reuse as tanks. The spent bleach bath contains all of the alkali and heat necessary for the Loading Bath for Next Lot next bleaching operation. Peroxide and One simple technique that saves water chelates must be added to reconstitute the and, in some cases, BOD loading is to bath. Like dyebath reuse, the number of reuse the final bath from one dyeing cycle reuse cycles in bleach bath reuse is limited to load the next lot. This technique works by impurity buildup. The main impurities well in situations where the same shade is are metals, such as iron, that can interfere being repeated or where the dyeing with the bleaching reaction. machine is fairly clean.

New types of rope bleaching units for A good example of this technique is acid knits featuring six to 12-stage jet transport dyeing of nylon hosiery. The final bath systems have made continuous bleaching usually contains an emulsified softener of most knit styles possible. These units that exhausts onto the substrate, leaving were introduced in the late 1970s and the emulsifier in the bath. This technique typically produce 40 pounds per minute of can serve as the wetting agent for loading knit fabric or more than one million the next batch, thus saving the water, pounds per month based on a three-shift, heat, and wetting agent and associated six-day operation. These machines have BOD. become very popular with large knit

F O O D & B E V E R A G E Water Conservation Techniques

In the food and beverage industry, water the many benefits of reducing water plays a significant role in transporting, usage. The following section discusses the cleaning, processing, and formulating methods and techniques many facilities products as well as meeting many federal have used to implement a successful water sanitary standards. Facilities implement- conservation program while maintaining ing water conservation programs some- production requirements. times struggle to balance these needs with

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For general rinsing and cleaning opera- wash water efficiency. tions, refer to Chapter 4 on cleaning, n Divide spray wash units into two rinsing, and in-process water reuse. or more sections, and establish a Several opportunities in the beverage counterflow reuse system. industry include: n Control belt sprays with a timer to allow for intermittent application n Adjust pump cooling and flushing of chlorinated water. water to the minimum required. n Figure 32 provides a listing of n Investigate potentially reusable potential reuse areas for specified discharges including final rinses canning operations. from tank cleaning, keg washes, fermenters; bottle and can soak and rinse water; cooler flushwater; filter backwash; and pasterizer and sterilizer water. n Potential areas for reuse include first rinses in wash cycles; can shredder; bottle crusher; filter C A S E S T U D Y backflush; caustic dilution; boiler make-up; refrigeration equipment Case Study: Recycling Transport Water defrost; and floor and gutter wash. Sparta Foods in Minnesota hired an intern to evaluate water usage in corn Several opportunities in the food industry processing. For the transport water use include: (5,200 gallons per day) the intern investi- gated alternative dry methods: 1) screw n Recycle transport water where conveyors were unacceptable because feasible. of degradation of corn, 2) belt conveyors n Use conveyor belts for product on the vertical cook tanks where a transport. Preference should be potential solution but only reduced given to “rabbit-ear” or V-shaped water by 10 percent making the intial roller supports because these are investment is unjustifiable. The intern much easier to clean. found that 20% of transport water could n Use pneumatic conveying systems be recycled without effecting product where practical. quality (concerns included pH and n Use flumes with parabolic cross- cleanliness). Recycling 20 percent would sections rather than flat bottom reduce total plant water usage by 3.5 troughs. percent and save $1,570 annually. n Consider these alternatives to water-intensive units: 1) rubber- disc units instead of raw product cleaning and peeling; 2) steam instead of water blanchers, 3) evaporative coolers instead of water cooled systems. n Establish optimum depth of product on conveyors to maximize

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FIGURE 32

Potential Water Reuse for Selected Food Processing Operations

Can reserved Can effluent Source of Operation water be used? be used? make-up water

Acid dip for fruit yes no can coolers Washing of product First wash, followed by second wash yes yes1 can coolers Final wash of product no yes1 can coolers Flumes Fluming unwashed or unprepared product yes yes1 can coolers Fluming partially prepared product yes yes1 Fluming fully prepared product no yes any wastewater Fluming waste yes no can coolers Lye Peeling yes no Product holding vats (covered with water or brine) no no Blanchers, all types Original filling water no no Replacement of make-up water no no Salt brine quality graders with fresh water final wash yes this operation Washing Pans and Trays Tank washers, original water no no Spray or make-up water no no Lubrication of product inside machines no yes1 can coolers Washing cans after closing no no Brine and syrup yes yes1 can coolers Processing jars and underwater no Can coolers yes this operation can coolers Cooling canals original make-up no yes2 make-up water yes yes2 Continuous cookers (cans partially immersed) originial make-up no yes2 make-up water yes yes2 Spray coolers with cans not immersed yes yes Batch cooling in retorts yes yes2 Clean-up purposes Preliminary wash yes yes1 can coolers Final wash no no Box washers yes no can coolers 1 - Use in preceding operation under precautions, 2 - Use in can coolers if quality is maintained.

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F O O D Water and Wastewater Use in the Food Processing Industry*

The following sections discuss major water using and waste generating processes in fruit, vegetable, dairy, meat, poultry, and oil processing. The information is provided to help food processing managers evaluate water use performance and consider additional water efficiency mea- sures. In the absence of water use data, wastewater (hydraulic) load- ings information is presented as a reference for water use.

The fresh pack segment of the industry Fruit and Vegetable shares unit operations with the processing Processing segment. These operations are the sort- The fruit and vegetable processing indus- ing/trimming, washing, grading, and tries may be described as consisting of two packing lines. But after the packing lines, segments: fresh pack and processing. The additional unit operations may add to the former collects crops and field packs them waste generating scheme for the process- into lug boxes or bulk bins for shipment ing segment alone. Additional operations to a produce finishing plant. Crops are may include combinations of peeling, cooled to preserve integrity and fumi- stemming, snipping, pitting, trimming, gated or treated to control insect infesta- chopping, and blanching. In some in- tion or microbial disease development. stances, the final product is dehydrated The processing segment, or packers, (e.g., chopped onions). In others, it is includes all unit operations, extending the packaged and processed. Processing can shelf life of food being processed and include one treatment or a combination adding value through produce modifica- of several treatments (e.g., acidifying, tion to satisfy market niches. brining, freezing, or cooking).

* Excerpts from “Waste Management and Utilization In Food Production and Process,” CAST, October 1995.

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Major water use and waste generation as well as filling and sanitizing activities points associated with the fruit and after processing, also contribute to the vegetable industry include the washing wastestream. steps for raw and processed produce, peeling and pitting practices, blanching, Wastewater Characterization fluming the produce after blanching, Major wastewater characteristics to be sorting, and conveying the product within considered for the vegetable and fruit the plant. Reducing size, coring, slicing, processing industry are the wide ranges of dicing, pureeing, and juicing process steps, wastewater volume and the concentra-

FIGURE 34 Representative Wastewater Loadings Per Ton of Product Associated with Typical Vegetable and Fruit Raw Products

Flow Flow Flow Crop (1,000 gal/ton) minimum (1,000 gal/ton) mean (1,000 gal/ton) maximum Vegetable products Asparagus 1.9 8.5 29.0 Bean, snap 1.3 4.2 11.2 Broccoli 4.1 9.2 21.0 Carrot 1.2 3.3 7.1 Cauliflower 12.0 17.0 24.0 Pea 1.9 5.4 14.0 Pickle 1.4 3.5 11.0 Potato, sweet 0.4 2.2 9.7 Potato, white 1.9 3.6 6.6 Spinach 3.2 8.8 23.0 Squash 1.1 6.0 22.0 Tomato, peeled 1.3 2.2 3.7 Tomato, product 1.1 1.6 2.4

Fruit Products Apple 0.2 2.4 13.0 Apricot 2.5 5.6 14.0 Berry 1.8 3.5 9.1 Cherry 1.2 3.9 14.0 Citrus 0.3 3.0 9.3 Peach 1.4 3.0 6.3 Pear 1.6 3.6 7.7 Pineapple 2.6 2.7 3.8 Pumpkin 0.4 2.9 11.0

86 Chapter 5 tions of organic materials. Wastewater processing industry is essential to characteristics can be influenced by a the washing, heating, and cooling number of factors such as the commodity of food products. But the industry processed, the process unit operations has adopted a number of practices, used, the daily-production performance showing heightened sensitivity to level, and the seasonal variation, e.g., the need for water conservation: growing condition and crop age at har- vest. Figure 34 presents historical data 1. Use of air flotation units to collected from raw wastewater discharged remove suspended debris from the vegetable and fruit processing from raw crop materials industry. 2. Recovery and reuse of process water throughout Water Use and Wastewater Sources the processing plant. In the processing environment for veg- 3. Decrease of water volume etable and fruit material handling, use in peeling and pitting heating, cooling, and packaging, there are operations, as well as six major contributing point sources for decrease of raw product losses. waste. These sources are the following 4. Separation of waste process operations: (1) raw produce washing, streams at their sources, for grading, and trimming, (2) washing after potential by-product use. steam/lye peeling and/or size reducing, 5. Countercurrent reuse of wash and (3) blanching and fluming, (4) filling, (5) flume/cooling waters. sanitation/plant cleanup, and (6) pro- 6. Separation of low and high cessed product cooling. Plant manage- strength wastestreams. ment practices greatly influence process 7. Installation of low-volume, high- operation efficiency relative to final pressure cleanup systems. product yield and waste quantity gener- 8. Conversion from water to steam ated. (Refer to Figure 34 for industrial blanching. variability.) 9. Use of air cooling after blanching.

Water Use and Waste Fruit Processing (Canning, Minimization Freezing, Fermenting, etc.) Ideally, considerable waste reduction can The initial preparation processes for be achieved if harvesting equipment canned, frozen, and fermented fruits are permits additional stems, leaves, and washing, sorting, trimming, peeling, culled materials to remain in the field pitting, cutting or slicing, inspecting, and during harvest. If crop washing, grading, grading. Unwanted and undesirable and trimming can occur in the field, then materials must be removed before the additional soil and food residues will fruits undergo additional processing, but remain at the farm. Realistically, most not all fruits are subject to each step. For such wastes are being handled at veg- example, cherries and plums may be etable and fruit processing plant sites. canned whole and unpeeled whereas Primary waste-management strategies apples, peaches, and pears must be peeled used by this industry are water conserva- and either cored or pitted before being tion and waste-solids separation. canned. Peeling can be by hand or with machines, chemicals, or steam. After Water use by the vegetable and fruit

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FIGURE 35 conveyors for flumes, the use of automatic shut-off valves on water Wastewater Loadings Per hoses. n The separation of can cooling ton of Product from water from composite wasteflow. n The recirculation of can cooling Canned Fruits water. When can cooling water is Flow not recirculated, it may be reused Fruit (gallon/ton) in caustic soda (NaOH) or in water peeling baths, in removal of Apple 500,000 NaOH after peeling, in primary Apricot 500,000 wash of the raw material, in canning belt lubrication, and in Cherry 200,000 plant cleanup operations1 . Citrus 300,000 Peach 400,000 Dairy Processing Pear 400,000 The processing of dairy products often Pineapple 50,000 entails various unit operations. These Other fruit 800,000 generally include the receiving and the storing of raw materials, the processing of raw materials into finished products, the packing and the storing of finished goods, inspection and grading, the peeled fruits and a number of ancillary processes (e.g., are conveyed mechanically or flumed to heat transferring and cleaning) associated product handling equipment for process- indirectly with processing and distribut- ing. ing.

The converted fruit handling processes Equipment and facilities for receiving, are can filling, syrup adding, exhausting transporting, and storing raw materials and sealing, thermoprocessing, can are much the same industrywide. Bulk cooling, and storing. Processing equip- carriers unload products in receiving areas ment and plant floor usually are cleaned by means of flexible lines or dump mate- at the end of each shift and so constitute rial into hoppers connected to fixed lines a final source of waste materials. subsequently transferred by pump to storage. Storage facilities can be of the Water and Wastewater Management refrigerator, vertical, or silo type, with Several water conservation and waste storage tanks containing either liquid or prevention techniques are available by dry products and ranging in volume from which to decrease water volume. These a few thousand gallons to one million techniques include gallons or more.

n The use of high-pressure sprays for Milk, a perishable product made up of fat, clean-up. protein, carbohydrates, salts, and vita- n The elimination of excessive mins, is an ideal food for microorganisms overflow from washing and as well as for humans. Thus, it needs to be soaking tanks. protected from contamination, and much n The substitution of mechanical of the efforts of the dairy industry are

88 Chapter 5 directed to this end. Milk and its by- Water use in the dairy products products are processed according to industry depends on plant approved procedures, on machinery complexity and water-manage- normally run no longer than about 20 ment practices. Process hours per day. Much equipment is dis- wasteloads also differ consider- mantled daily. Systems may be cleaned in ably and are influenced greatly place or after they are taken apart. by the extent to which the plant Automated cleaning systems, now pre- controls raw material and dominant in the industry, require less product losses. Raw wastewater labor but more water and cleaning loading for the American dairy chemicals than hand washing dismantled industry is summarized by equipment does. commodity segment in Figure 36.

Wastewater and Management Milk product losses typically range from Dairy processing wastewaters are gener- 0.5 percent in large, technologically ated during the pasteurization and the advanced plants to greater than 2.5 homogenization of fluid milk and the percent in small, old plants. Given re- production of dairy products such as doubled effort by management, water butter, ice cream, and cheese. The princi- usage in most plants could be decreased to pal constituents of these wastewaters are approximately 0.50 L/kg milk equivalent whole and processed milk, whey from processed. Considerable improvements in cheese production, and cleaning com- water and waste management remain pounds. important and realistic industry goals.

FIGURE 36 Summary of American Dairy and Milk Processing Plant Effluent Loadings Wastewater Wastewater Products (kg ww/kg milk) range (kg ww/kg milk) average

Milk 0.10-5.40 3.25 Cheese 1.63-5.70 3.14 Ice cream 0.80-5.60 2.80 Condensed milk 1.00-3.30 2.10 Butter 0.80 Powder 1.50-5.90 3.70 Cottage cheese 0.80-12.40 6.00 Cottage cheese and milk 0.05-7.20 1.84 Cottage cheese, ice cream, and milk 1.40-3.90 2.52 Mixed products 0.80-4.60 2.34

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Innovations Waste and By-Products In recent years, technological innovations Most waste products are recovered some- with membrane systems have provided how by the industry. Blood, feathers, and many new opportunities. For example, bone usually are processed into a meal ultrafiltration now can be used instead of product for animal feed. Similarly, meat the biological separation of organic scraps unsuitable for processing into food material from liquid substrate. And products are sold or given to rendering instead of using reverse-osmosis systems facilities for processing into animal and for tertiary waste treatment, some food pet foods. The ultimate characteristics of plants use them to recycle internal liquid solid materials and wastewaters generated wastestreams. The outflow from reverse- by these source areas in a plant and osmosis treatment can be of better quality unrecovered for another use differ greatly than the native water. and are affected by:

Meat and Poultry Processing 1. animal size and type 2. processing level The meat and poultry processing indus- 3. conveyance means tries in the United States together make 4. processing water use up a $75.6 billion per year industry. The 5. cleanup and housekeeping proce- U.S. Department of Commerce reported dures that the value of red meat shipments for 1988 totaled $46.8 billion. Most red meat processing plants are located in the Water Usage Midwest; most poultry processing plants Water use for broiler processing typically are in the Southeast and the Mid-Atlan- ranges from 3.5 to 10.0 gal./bird; for tic. Processing of prepared meats, includ- turkeys, 11 to 23 gal./bird. Flow rates of ing canned cooked products, luncheon 350 gal./animal have been reported for meats, hot dogs, bacons, stews, and other beef slaughtering plants. In one beef ready-to-eat meat products, has expanded slaughtering operation, water use dropped rapidly in recent years. from 458 to 187 gal/head after water conservation measures were adopted. Similar water use numbers appear in the examples in Figure 37.

Water is used for chilling, scalding, can FIGURE 37 retorting, washing, cleaning, and waste conveying. For example, poultry process- Typical Water Consumption ing uses approximately 3.5 to 7.0 gallons for Beef, Turkey, and Broiler of water per bird of four-pound average weight. All broiler processing plants are Processing required to have a scalder overflow rate Water of 0.25 gal./bird and a chiller overflow Animal type (gallon/animal) rate of 0.50 gal./bird. In many instances, this water is used in the plant for the transport of feathers and offal from the Beef 150 - 450 processing area. One researcher, studying Turkey 11 - 23 a broiler processing plant, reported that Broiler 3.5 - 10 processing accounted for 76 percent of

90 Chapter 5 the water use, with 13 percent used in reviews major processes and facilities, cleanup and 12 percent used in down- especially as they relate to waste genera- time. tion and control.

Beef processing water usage, primarily Process Components and Major from carcass washing and process clean- Wastewater Sources up, has been reported in the range of 150 Figure 38 lists primary processes and to 450 gallons per animal processed. As a associated wastewater loadings from a general rule, meat processors use about well-run fat and oil processing facility. one gallon of water per pound of pro- Separate totals are presented with and cessed hamburger meat. without salad dressing and mayonnaise because these processes often are absent Use and Minimization of Wastes in a facility. Certain oil processing and The amount of wastewater generated by refining operations have no oil seed the industries can be decreased largely processing facilities, but instead bring in through changes in cleanup practices. crude vegetable oil. To account for this Water use can be minimized by means of practice, adjustments can be made to the commercially available high-pressure, figures in the table. Data presented in restricted flow hoses, which can be fit Figure 38 are based on these operating with automatic shutoffs to prevent water parameters: loss during inactivity. Many materials can be handled mechanically. For example, 1. Milling and extracting: 80,000 flour and other dry material can be bushels per day. vacuumed from the floor and augers and 2. Caustic refining with single-stage conveyors can be used to transport scrap water wash:60,000 lb/hr, meat and viscera. nondegummed soybean oil. 3. Semicontinual deodorizing with Chiller and scalder water is reused in scrub cooler, barometric con- most poultry processing plants for flush- denser with atmospheric cooling ing water to remove offal and feathers. tower. Reconditioning of chiller overflow 4. Acidulating of soapstock and through the use of filtration and ultravio- washwater with 90 to 95 percent let irradiation has been recommended. recovery efficiency. Limits to use include the potential of 5. Bottling line and/or other exten- bacterial contamination by coliforms or sive liquid-oil packaging. by Escherichia coli. Recycling is limited by 6. Margarine, mayonnaise, and salad the characteristics of the wastestream and dressing production and packag- by the potential for contamination of ing. food products. 7. Washing of tank cars for finished oil only (cars carrying crude oil Grain Processing for Oils excluded). The extracting, refining, and processing Obviously, operations of an atypical size of edible oils produces a variety of waste or those omitting certain processes will products. This chapter, which focuses on have different waste loads. This applies conventional caustic refinements and on especially to operations involved in related downstream processes, briefly acidulation or in mayonnaise and salad

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FIGURE 38 dressing processing. The effects of process control and its impacts on wastewater Fats and Oils Processes and loading are outlined in the next section. As noted, these loadings are representa- Wastewater Loads tive for an operation running reasonably well from a process loss control stand- from a Well-run Facility point. But actual loadings depend on how Flow well plants are run. Process (gallons/daya, avg.) A final source of wastewater is contami- Milling and extraction 75,000 nated runoff from truck and rail loadout Caustic refining 11,000 areas and from tank farm drainage. During rainy periods, runoff from these Further processing 5,000 sources can contribute the equivalent of Deodorizing 5,000 five to 10 gal/min to total daily average Acidulating 19,000 flow and, in fact, may affect peak flows to Tank car washing 5,000 a much greater extent. Packaging 10,000 Subtotal 130,000 Margarine 70,000 Salad dressing/mayonnaise 50,000 Total 250,000

agallons/day = gallons per day

92 .._ .’

Rinsewater feed Rinsewater feed Rinsewater feed

Work Flow

During the past 15 years,t he metal .$SSPo tentiallyimproving pollutant finishing industry has madegrea tstrides removale fficiencyin wastewater in reducingwa teruse .I n a 1994survey by treatment. the National Associationo f Metal Finish- Reducingor delayingneed f or ers, 68 percento f respondentshad made treatment capacityexpansion . substantialreduc tionsin water use throughpollution preventiont echniques. Improvingrinsing efficiencyrepresen ts On averagethese, shops had reduced the greatestwa ter reductionop tion for water flow by 30 percentor about 20,000 metal finishers.A rinsing efficiency gpd. Evenwith theseachievemen ts,me tal programalso is the first stept o enable finishingbusinesses still continuet o have metal finisherst o implementprogressive largeoppor tunitiest o further reduce pollution preventiont echniquessuch, as water use.Wa ter efficiencywithin an chemicalrecovery from the more concen- integratedpollution preventionprogram trated wastestreamand the potential of can providet heseadvan tagesfor metal closed-loopingthe electroplatingprocess. finishers:

Loweringopera tioncost by reducingwa ter bill. -g Reducingwastewater treatment In the metal finishing industry, rinsing costs. qualityhas a dramatica ffect on product Chapter 5

M E T A L F I N I S H I N G

FIGURE 39

Rinse water feed Rinse water feed

Alkaline Acid "pickle" Electropl Rinse Rinse Cleaner Surface prep Proces

Work Flow

During the past 15 years, the metal n Potentially improving pollutant finishing industry has made great strides removal efficiency in wastewater in reducing water use. In a 1994 survey by treatment. the National Association of Metal Finish- n Reducing or delaying need for ers, 68 percent of respondents had made treatment capacity expansion. substantial reductions in water use through pollution prevention techniques. Improving rinsing efficiency represents On average, these shops had reduced the greatest water reduction option for water flow by 30 percent or about 20,000 metal finishers. A rinsing efficiency gpd. Even with these achievements, metal program also is the first step to enable finishing businesses still continue to have metal finishers to implement progressive large opportunities to further reduce pollution prevention techniques, such as water use. Water efficiency within an chemical recovery from the more concen- integrated pollution prevention program trated wastestream and the potential of can provide these advantages for metal closed-looping the electroplating process. finishers: Improving Rinse Water n Lowering operation cost by reducing water bill. Efficiency n Reducing wastewater treatment In the metal finishing industry, rinsing costs. quality has a dramatic affect on product

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quality. Improvements in rinsing effi- by properly placing inlets and ciency must be carefully integrated into outlets on opposite ends of the quality control and assurance programs. tank. Rinsing efficiency improvement tech- n Use inlet flow baffle, diffusers, niques for metal finishers include im- distributors or spray heads. proved rinse tank design, flow control n Select the minimum sized tank techniques, and alternate rinse tank appropriate for all parts/products. configurations. (See Figure 40.) n Consider spray rinsing instead of immersion for flat-surfaced parts. Rinse Tank Design n Consider ultrasonic rinsing applications where applicable. Proper design of rinse tanks will improve rinsing efficiency and reduce water use. Optimum rinse tank designs provide fast Flow Control Techniques removal of chemical solutions or “drag- Flow Restrictors out” from the parts. These techniques can The use of flow restrictors is a very enhance rinse tank design: effective means to ensure excessive water is not fed to the process line. Flow n Provide agitation to tank by air restrictors are installed in the feed line of blowers (not compressed air), a tank. They are commonly elastomer mechanical mixing, or pumping/ washers with an orifice that is squeezed filtration systems. smaller with increasing line pressure. n Prevent feed water short-circuiting They are available in rates ranging from

FIGURE 40

Survey Rinse Water Efficiency Applications

Percent of business Success Technique using technique rating2

Flow restrictors 70 4.1 Counter current rinse 68 4.2 Manually turn off rinse water when not in use 66 3.6 Air agitated rinse tanks 58 3.7 Spray rinses 39 3.8 Reactive or cascade rinsing 24 3.8 Conductivity controllers 16 3.3 Flow meter or accumulator 12 3.7 Timer rinse controls 11 3.25

1Based on NCMS/NAMF study in 1994 – 318 metal finishers responding. 2Success rating based on scale of one to five with five being highest.

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0.1 gpm to greater than 10 gpm. The flow rate of a restrictor should be chosen to provide sufficient water for quality rins- ing. Restrictors work best in consistent C A S E S T U D Y production applications. Conductive Controller Flow Cut-off Valves (Manual and Automatic) Water flow to rinse tanks should be shut Artistic Planting and Metal Finishing in off when the process lines are not in use. Anaheim, California, installed This can be done manually or automati- electrodeless conductivity controllers on cally. A foot actuated feed valve can be nine rinsing tank systems. Artistic Plating used in job shops that have discontinuous is saving 55,000 gallon per week, which processing demands. The rinse water equates to a 43 percent rinse water valves can be activated only when compo- savings. The conductivity system resulted nents are being rinsed. For larger continu- in decreased rinse water use, wastewater ous operations, solenoid valves can turn generation, wastewater treatment off rinse water lines when power to the chemical use, and sludge generation. electroplating line is turned off. For Artistic Plating experienced no adverse automatic conveyorized lines, quality effects using the controller. Total photosensors also can be used to turn on system payback was one year. water valves or spray heads only when parts are passing that rinse stage.

Conductivity Meters and Controllers FIGURE 41 The most accurate way to control rinse water flows and purity can be achieved Acceptable Rinse Water using conductivity controls. The use of conductivity meters and control valves will Contaminant Limits substantially reduce rinse water flow and Conductivity in ensure a set water purity standard is µ Rinse bath for micromhos ( mho) always being met in the tank. Electrical conductivity increases as the concentra- tion of contaminant ions increases. Alkaline cleaner 1,700 Hydrochloric acid 5,000 Conductivity meters indicate the concen- Sulfuric acid 4,000 tration of contaminant ions in the rinse µ Tin acid 500 water in units of micromhos (µmhos), also referred to as microsiemens. Specific Tin alkaline 70-340 conductance can be roughly correlated to Gold cyanide 260-1,300 total dissolved solids (TDS) in mg/L using Nickel acid 640 empirical data. Zinc acid 630 Many metal finishing facilities have Zinc cyanide 280-1,390 installed conductivity controllers on the Chromic acid 450-2,250 rinse tanks which trigger the introduction of fresh water only when the conductivity

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Portable conductivity meters also can be used to establish a fixed flow rate to C A S E S T U D Y maintain an appropriate rinse water quality. Once rinse water purity levels are Rinsing Efficiency established, permanent flow restrictor valves can be installed in the water supply line to the individual rinse tanks. This C & R Electroless Nickel in Gastonia, technique is suggested only where electro- North Carolina, reconstructed it plating production is consistent. Again, electroless nickel line to incorporate use Figure 41 as a starting point. several pollution prevention tech- niques and improve processing Flow Meters efficiency. Single-rinse tanks were Relatively inexpensive meters or accumu- switched to a system of multiple lators can be installed on the main water counterflow rinse tanks to reduce feed line to process line or on individual water consumption. Restrictive flow rinse tanks. While meters and accumula- nozzles on water inlets were added tors do not actually save water, they do to better control and reduce water allow for careful monitoring of usage and consumption. The process line can identify optimum water utilization (or upgrade reduced water consumption excessive waste), leaks, and system failures. by 87 percent, from 7,500 gallons to less than 1,000 gallons per day. Alternative Rinsing Configurations reaches a certain set point. This practice Counter Current Rinsing significantly reduces water consumption, Counter current rinsing is the practice of typically by 40. overflowing rinse water between a series of rinse tanks so that the water flow is in Conductivity rinse water flow controllers the opposite direction to work flow. This are most useful on discontinuous electro- results in the final rinse being the plating operations. The cost of installing cleanest. Counter current rinsing signifi- each rinse water conductivity controller cantly reduces water usage without sacrific- will be between $1,000 and $2,000 and ing rinsing efficiency. A common configu- typically will have an economic payback of ration for a counter current rinse is two about one year. In the past, conductivity to three rinse tanks in series. Water controllers required high maintenance to consumption can be reduced more than prevent fouling of electrodes. Newer 90 percent just by adding a second inductive loop or electrodeless sensors are counter flowing rinse to a single rinse less susceptible to fouling than conven- tank. (See Figure 42.) tional electrode types. Determining the optimum set point for these controllers If floor space is a problem, a partition also is imperative to conserve water and could be installed in the existing rinse maintain quality. Figure 41 can be used as tank with a metal divider acting as a weir. a starting point for determining accept- This modification can be made only if able rinse water purity standards. there is sufficient room for the parts rack or barrel in the tank.

96 Reactive Rinses and Reuse critical rinse in the same processingline or A reactive rinsing system involves diverting between processing lines. Care should al- the overflow from an acid rinse to an alka- ways be taken to ensure cross contamina- line rinse tank. (SeeFigure 43.) The acid ions tion is not problematic. neutralizethe alkaline ions without causing contamination of the rinse water or com- spray Rinsing promising plating quality. By reusing acid Spray Rinsing can be incorporated into rinse baths for alkaline cleaner rinses, the existing metal finishing processlines to effectivenessof the alkaline cleaner rinses further reduce water use. Typically, spray can be improved while reducing water con- rinses can be used directly over heated sumption by 50 percent. Furthermore, the processtanks or over a dead rinse to rinse water from single rinse stagesfollow- reduce drag-out. By spraying drag-out back ing plating baths has been shown to effec- into its processtank or into a concen- tively clean products in rinses following acid trated holding tank, less water will be or alkaline cleaning without affecting the needed for final rinsing. Spray nozzlesfor rinse effectiveness.Rinse water sometimes these applications typically have flow rates can be reusedfrom a critical rinse to a less ranging from .04 to 1.0 gpm. Nozzles can

Improved Washing/Rinsing Line Schematic (Cross-section View)

In-Tank CartrIdge Filter 8. BelWdlsWpig 011 SkImmIng (OptIonal) R,nse Water Feed (DI Suaaested)

Conductlwty feed-wate OptIonal rotating controller (optional)

counter counter current current De-Ionwed Rinse 1 Rinse 2 Final Rinse Cleaning Tank (heated)

AI agitation system Work Flow b

Water Balance X-Z=Y gph “X ’ must be determined by rinsing purity crlterla “X ’ IS dependant upon concentration of dragout solubon, rate of dragout. and rinsing purity Typically requwed rlnslng purity 1s 400.1000 mgll total contaminants “7 can be estimated by eq gal/WfPe n (0.02655T.5 95)vhere T = degrees F and ftV IS tank surface area (assumes agitated tank) r‘ ’ IS hydraulic wastewater loading (gph)

Good drag-out reduction practices strongly recommended 10 set dnp time over tank Chapter 5

Reactive Rinses and Reuse critical rinse in the same processing line or A reactive rinsing system involves diverting between processing lines. Care should al- the overflow from an acid rinse to an alka- ways be taken to ensure cross contamina- line rinse tank. (See Figure 43.) The acid ions tion is not problematic. neutralize the alkaline ions without causing contamination of the rinse water or com- Spray Rinsing promising plating quality. By reusing acid Spray Rinsing can be incorporated into rinse baths for alkaline cleaner rinses, the existing metal finishing process lines to effectiveness of the alkaline cleaner rinses further reduce water use. Typically, spray can be improved while reducing water con- rinses can be used directly over heated sumption by 50 percent. Furthermore, the process tanks or over a dead rinse to rinse water from single rinse stages follow- reduce drag-out. By spraying drag-out back ing plating baths has been shown to effec- into its process tank or into a concen- tively clean products in rinses following acid trated holding tank, less water will be or alkaline cleaning without affecting the needed for final rinsing. Spray nozzles for rinse effectiveness. Rinse water sometimes these applications typically have flow rates can be reused from a critical rinse to a less ranging from .04 to 1.0 gpm. Nozzles can

FIGURE 42

Improved Washing/Rinsing Line Schemat (Cross-section View)

In-Tank Cartridge Filter & Belt/disk/pig Oil Skimming (Optional)

"Z" gph out Conductivity fee Optional rotating controller (opt Barrel Set-up

"Z" evap. make-up

Manual Parts basket Counter Counter Current Current De Rinse 1 Rinse 2 Fin Cleaning Tank (heated)

"X" gph "X" gph

Rinsewater overflow "Y" gph Air blower agitation system Work Flow

Water Balance: X-Z=Y gph "X" must be determined by rinsing purity criteria. "X" is dependant upon concentration of dragout solution, rate of dragout, and rin Typically required rinsing purity is 400-1000 mg/l total contaminants. "Z" can be estimated by eq. gal/hr/ft^2 = e ^ (0.02655T-5.95) where T = degrees F and ft^2 is tank surface area (assumes agitated tank). "Y" is hydraulic wastewater loading (gph).

Good drag-out reduction practices strongly recommended: 10 sec drip time over

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FIGURE 43

Rinse Water Reuse and Reactive Rinsing

Alkaline Acid "pickle" Ele Rinse Rinse Cleaner Surface prep P

Work Flow

be hydraulic nozzles, which spray water n Operating bath formulations at a only or air-atomized nozzles which use minimum chemical concentra- compressed air. Nozzle spray patterns are tions. available in full cone, hollow cone, flat n Maximizing bath operating fan, and finer misting and fogging types. temperature to lower bath viscos- Spray angle and length of spray pattern is ity. important when specifying the number n Using wetting agents to reduce and spacing of nozzles. Components of surface tension. Up to a 50 per- spray systems include a water supply, filter, cent drag-out reduction can be switch, check valve, and nozzle(s). The achieved. approximate installed cost for a spray n Racking parts to maximize drain- system over an existing tank is less than age. Drag-out rates for very poorly $2,000. Case studies have shown these drained parts are three to 12 times systems are paid for in less than one year the rates for well drained parts in water and chemical savings. with vertical, horizontal and cup shaped surfaces. Reducing Drag-out to n Extending drainage time over process tank or dead rinse tank. Improve Rinsing n Increasing drip time from three to The term “drag-out” refers the residual 10 second reduces the drag-out solution that still is adhering to a part remaining on a part by an average when it leaves a process bath. The drag- of 40 percent. out is the solution that must be rinsed off n Using spray or fog rinsing over the the part. By employing techniques that process tank or dead rinse tank reduce the volume of drag-out, metal n Positioning drainage boards finishers can rinse parts using less water. between the process tank and next Potential drag-out reduction techniques rinse tank. for metal finishers include:

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By reducing the volume of process solu- wastewater reuse becomes more feasible tions carried out of the plating tank, from an operation standpoint. Some metal finishers can reduce rinse water, companies have successfully closed-looped conserve expensive bath formulations, electroplating rinse tanks by employing and directly reduce the pollutant mass continual cationic and anionic exchange loading to wastewater. reclamation of metals.

Wastewater Reuse An electro-coagulation/ultraviolet process patented by Pasco, Inc., has been success- Techniques fully applied to treat and reuse alkaline Some electroplating shops are reusing and acid rinse waters and bath dumps. treated wastewater for non-critical rinsing The process offers cost effective high steps such as after alkaline cleaners and quality water reuse and low sludge genera- acid pickling steps. The reuse of conven- tion due to no needed chemical additions tionally treated wastewater (via hydroxide for solids coagulation and flocculation precipitation) should be cautioned due to treatment stages. the introduction of high dissolved solids into the plating line. Drag-out and drag-in Other novel applications of wastewater from conventionally treated water can treatment techniques such as electro- contaminate other process baths with coagulation and absorptive/adsorptive contaminants such as sodium. In conjunc- media hold promise to enable tion with advanced membrane separation electroplaters to close loop their opera- techniques such as reverse osmosis, tions.

99 Chapter 6 Auditing Methodology 6 and Tools A facility water audit or survey is the key n Record the number of meals activity of any water efficiency program. served, number of guest This chapter provides supplemental rooms, and occupancy data for information and tools for the water audit service establishments, such as team conducting the plant survey. (Also restaurants, hotels, hospitals, see Chapter 3.) military bases, and schools. n For manufacturing sites, Water Audit Preparation identify the amount of water used per quantity of product Thorough preparation for the water audit produced (that is, gallons per will ensure maximum results and effi- ton of product or gallons per ciency. Collect the following information gross of widgets). regarding the facility’s water use, and n For schools and other such identify all personnel familiar with the institutions, record the operation. amount of water used per person per day. 1. The exact location of the facility included in the audit. 6. The operating schedule of the 2. The physical size of the facilities, facility, number of employees per including the number of buildings shift, maintenance shifts, and and floor space (in square feet) for other operating information. each. 7. A water use profile (graph) show- 3. Plumbing drawings, riser dia- ing the total water use and water grams, and irrigation plans. used per unit of product per 4. Names and phone numbers of month. facility contacts. 8. Copies of the proposed billing 5. Specific services or products rates for energy, water, and produced at the site: wastewater for the next two years. 9. List of all water-using equipment,

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including the manufacturer’s n Location of all water supply recommended flow requirements. meters that record deliveries 10. Inventories of sanitary fixtures from utilities, wells, and other and any water-saving features. water sources. 11. Outdoor water use and irrigation n Location of all on-site process controls. and building meters. 12. Previous water and energy surveys. n Sizes of all meters. 13. All water delivery records from water meters, tank trucks, or the 14. Any calibration test results for facilities’ own wells. Accurate meters to adjust past meter water meters are essential for a readings to reflect actual water valid water audit. Source water use. meters indicate the amount of water supplied to the site. Sub- If the firm has never performed a signifi- meters indicate water used for cant water efficiency study, experienced specific processes and individual help may be needed. Experienced assis- buildings on the site. Obtain the tants may be available from the following: following meter information before starting the audit: n Other units within the organiza- tion.

Measuring In-Plant Water Usage

Sub-metering is an excellent way to accurately account for large water uses in specific processing equipment for departments within the plant. Sub-metering helps personnel become familiar with water use for all operations and indi- cates whether equipment is using water when it is not needed. (In some rinses, water is left running continuously, even when the need is only occa- sional.)

To obtain the appropriate size for a sub-meter, use the actual flow rate rather than just pipe size. Use temporary strap-on meters to determine the approxi- mate flow. Then, the correct size of the positive displacement meter can be determined before installation. Temporary meters also will indicate whether it will be cost-effective to install permanent meters.

Bucket and stopwatch is a simple and accurate measurement tool. To use this method, collect a specified amount of process water for a specific time period (e.g., one quart per minute, which is equivalent to 0.25 gpm)

Micro-weirs are small hand-held weirs that are used to measure low flows of water (0.5 to six gpm) in tight spaces, such as under lavatory faucets.

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n Local, state, or university techni- 3. Measure the actual amount of cal assistance services. water being used. The most direct n Consultants who understand the way to measure flow rates is with a processes. bucket and a stopwatch. Consider n Water, gas, energy, and electric installing meters on major water- utilities. using processes or plant depart- ments to record the quantity of water used. Conducting the Water Audit 4. Check water quantity and quality The next step is to conduct a walk- of water specified within the through survey with facility personnel equipment operating manuals. who are knowledgeable of how water is Equipment sometimes is operated used in each area of the facility. Use at higher flows than required by direct observation and measurements. the manufacturer’s specifications. Identify and record all pieces of equip- Ask qualified engineers to review ment that use water. Check with equip- the specifications and adjust flows ment operators who may have important accordingly. Further, investigate first-hand information. Use the following whether the processes can still procedure to conduct the step-by-step operate properly with further survey. reductions in water flow. Be sure to record flow rates before and 1. During the walk-through, record after changes are made to evaluate hours of operation for each piece the effects of the reduced flow. of equipment. Identify water 5. Read water meters regularly and piping layouts, particularly in compare actual water use to the areas of older equipment, to aid facility’s water reduction goal. with identifying water uses. Note After determining daily use rates, those pieces of equipment that the frequency of the readings have multiple uses of water (e.g., should be adjusted to be consistent water-cooled ice machines). with the volume of water used, 2. Identify water flow and quality as the cost of reading the meters, needed for each use. This infor- and potential excessive use fees. mation may be needed to deter- For example, large water users mine if discharges from one use (more than 50,000 gpd) should can be re-used as a potential continue to read meters daily. supply for a different application. Commercial businesses using Include these parameters: water for sanitary purposes only might read meters biweekly or n Temperature. monthly. n Water quality indicator param- 6. Identify flow and quality of eters, such as pH, TDS, and wastewater resulting from each conductivity. use. n Other key water quality 7. Include any internally generated parameters such as BOD, fluids in the water audit. Water COD, metals, or oil and may be generated as a by-product grease. of processing raw materials, such as fruits or from oil/water separa-

102 Leak Losses for Circular Holes

2.5

2

20 (psi) 1.5 40 (psi) 60 (psi) gpm 1 80 (psi) 100 (psi)

0.5

0 0.01 0.025 0.05 0.075 0.1 Diameter of Hole (in) Chapter 6

tion equipment. Determine the consider having a leak detection survey quantity and quality of these fluids conducted by a consulting or service firm. and whether there are potential Sonic leak detection equipment ranges in on-site uses for these fluids, such price from $900 to more than $4,000. as housekeeping or cooling. Determining Water Loss Use survey results to prepare a water balance diagram (See Figure 10, Chapter 3.) by Leaks to depict all water uses from source Determine the volume of water loss by through on-site processes, machines, and leaks is importance to determine both buildings, and finally, to evaporation and water and cost savings by repairing the discharge as wastewater. If unaccounted leak. One of the simplest methods to for water is greater than 10 percent, determine leak loss is the bucket and revisit the major areas of water use, talk stopwatch method. A small drip also can further with plant operators, or take additional measurements. FIGURE 44 Drips/Second to Leak Detection All facilities will experience some leaks. GPM Conversion Leaks may range from a fraction of a No. drips Gallons per percent up to several percents of total per second minute water use. Common locations to find leak are in piping joints, restroom fix- 1 .006 tures, pump seals, hose nozzles/shut off 2 .0012 valves, drinking fountains, processing 3 .018 equipment, and other locations. Elimi- nating leaks typically includes tightening 4 .024 or replacing fitting. 5 .030

Five drips per second is a steady stream. Leaks can best be identified by visual or audio observation. Water fixtures and process equipment should be observed both during use and during down time. All employees should be Leak Losses for Circular Holes responsible for notify maintenance personnel 2.5 of leaks, and mainte- 2 nance personnel should 1.5 make leak repair a

priority. Underground gpm 1 and under-the-floor leaks 0.5 can be detected through a leak detection survey. If 0 an underground leak is 0.01 0.025 0.05 0.075 0.1 suspected, but not identi- Diameter of Hole (in) fied, facilities should

FIGURE 10345 Chapter 6

be measured by the bucket and stopwatch method. Mathematical estimates of leaks also can be used. Water Leak Equations Water Meter Issues Rates of water loss for a roughly circular hole can be The size and accuracy of a facility’s water estimated using the Greeley equation (See Figure 45.): meter is important when accurately accounting for water use. Typical type of Q = (30.394)(A)(square root of P) meter use for commercial and industrial Where Q is leak rate in gpm, A is the cross-sectional setting include positive displacement, area of the leak in square inches, and P is the line turbine, and compound meters. Figure 46 pressure in pounds per square inch (psi). shows typical applications for meter types and sizes. Water meters can become less Leaks in joints or cracks can be estimated by this accurate when the intended water use of a equation: facility has changed or when substantial water conservation activities have been Q = (22.796)(A)(square root of P) implemented. Water meters should be of Where Q is leak rate in gpm, A is the area of the leak adequate size but not oversized. If a meter in square inches, and P is the line pressure in psi. For is oversized for the facility’s needs, the example a 1/32” wide crack, 1” long will lose 4.5 gpm facility could be paying unwarranted at 40 psi. service charged for the oversized meter. Properly selected and sized water meters can become inaccurate due to wear, which is affected by age and water quality. In-place field testing using a pitotmeter for large meters and portable meter test unit for smaller water meters can be FIGURE 46 conducted.

Types of Meters and Applications Type Common sizes Typical Applications

Positive 5/8 - 2 inches Commercial, medium hotels, apartment displacement complexes, and industrial plants Class II Turbine 2 - 6 inches Medium/large hotels, large apartment complexes to large manufacturing and processing plants Class I Turbine 8 - 12 inches Industrial, manufacturing, processing, pump discharges Compound, high 2 - 4 inches Medium hotels have special high and low velocity styles demands for schools, public buildings, and hospitals

104 Chapter 6

Water Survey Data Sheet

This data collection sheet is designed to assist auditors during assessments. Some items may not be appropriate for all assessment situations.

Assessment Information

Company name ______Date of assessment ______

Address ______

Phone/fax ______Audit coordinator ______

Assessment team members ______

Assessment objectives (special concerns) ______

Background Information About Water Use

Average water use/bill (for previous year) ______

Average sewer use/bill (for previous year) ______

Size and location of meter(s) ______

Primary water source ______

Secondary water source ______

Number of employees ______Shifts per day _____

Operating days per week ______Size of plant (square feet) ______

Type of facility (manufacturing, college, health care, office, etc.) ______

If manufacturing, list products and annual production rate. ______

If service or institutional sector, list clients, occupancy rates, and meals served per year, etc. ______

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Other pertinent facility data ______

Current and past water efficiency program measures (policies, training, awareness, and

goals) ______

System Parameters Number, types, and sizes of buildings at complex ______

Grounds (approximate area in acres) ______Garages/motor pool/support

buildings (approximate square feet) ______

On-site water treatment description, rate, and costs ______

Wastewater treatment description, rates, and operating costs ______

Water Use in Manufacturing Processes Volume used directly in the product per year ______

Description of water uses in processing ______

Volume used in production processes (i.e., plating) ______

Comments ______

Washing and Sanitation Volume used for cleaning, washing, and sanitation ______

Description of washing and sanitation practices ______

Cooling and Heating

Description of cooling tower/evaporative coolers (rated tonage, types, and uses) _____

______

Water rate used in cooling towers and equipment ______

Description of once-through cooling requirements ______

Volume used in once-through cooling (air compressors, air conditioners, vacuum pumps,

rectifiers, hydraulic equipment, degreasers, etc.) ______

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Volume used in boiler blowdown and steam ______

Domestic Toilets (number, types, and tank volumes) ______

Urinals (number and volumes) ______

Lavatory sinks (number and estimated flow) ______

Showers (number and estimated flow) ______

Other ______

Landscaping/Outdoor Use Landscape irrigation (estimated gallons per unit of time) ______

Acreage/square footage landscaped and description ______

Watering/irrigation system, techniques, and schedule ______

______

Others/Comments ______

Kitchen/Canteen

Dishwasher(s) description and use ______

Volume used for dishwashing ______

Kitchen faucet/pre-rinse sprayers [number and flow rate (gpm)______

Ice makers, air or water cooled, and water usage ______

Garbage disposals in use? ______

Comments ______

Other Uses, Leaks, and Unaccounted for Water List any quantifiable leaks and estimated rates. ______

Other uses of water (air washers, wet scrubbers, ornamental ponds, dust control, etc.)

______

107 Chapter 6

Selected Ideas for Efficiency and Cost Savings Low-flow plumbing fixtures ______Timers/electric eyes, etc. ______

Re-use of water in process ______Gray water reuse potential ______

Use cooling jackets with temperature sensors ______

Use chillers/preventing evaporation losses ______

Xeriscaping (use of certain plants, landscaping, etc.) ______

Drip irrigation versus overhead or spray watering ______

Effectiveness of air cooling versus water cooling ______

Effect of piping friction and heat loss ______

Potential to reduce meter size ______

Inspected for leaks ______

Obtain credit for water, which does not go into sewer (i.e., manufacturing uses, lawn

uses, etc.) ______

Install additional meters to monitor water not being sewered ______

Employee education and training needs ______

Other ______

Additional Comments Factors that could affect, increase, or decrease in water use ______

Other major inefficiencies uncovered and assessment opportunities, such as lighting,

solid waste reduction, heat recovery, pollution prevention, etc.) ______

______

Positive recognition ideas for previous water efficiency measures ______

Other ______

108 Chapter 7

Resources

National7 Water Efficiency Programs North Carolina American Water Works Associa- tion and Water Environment Association Waterwiser P.O. Box 11322 6666 West Quincy Avenue Raleigh, NC 27604 Denver, CO 80235 Phone: (919) 387-0646 Phone: (800) 559-9855 Web site: http://www.waterwaiser.org The Waterwiser clearinghouse is a unique information Landscaping Associations source created to assist water professionals and other interested parties with locating current and comprehen- The Irrigation Association sive information about water efficiency topics. 8261 Willow Oaks Corporate Drive Waterwiser has a wide array of information services, Suite 120 including an on-line conference. Fairfax, VA 22031 Phone: (703) 573-3551 U.S. EPA’s Water Alliances of Voluntary Efficiency Fax: (703) 573-1913 (WAVE) Program Web site: http://www.irrigation.org U.S.EPA 401 M Street SW (4204) American Society of Irrigation Consultants Washington, DC 20460 P.O. Box 426 Phone: (800) 993-7288 Byron, CA 94514-0426 Web site: http://es.epa.gov/partners/wave/ Phone: (925) 516-1124 wave.html Fax: (925) 516-1301 The Water Alliances for Voluntary Efficiency (WAVE) Web site: http//www.asic.org program’s mission is to encourage commercial businesses and institutions to reduce water consumption while increasing efficiency, profitability, and competitiveness. North Carolina Assistance Providers Initially limited to the hotel/motel sector, the program is Addressing Water Efficiency, Pollution expanding to assist other businesses sectors. Prevention, and Energy Efficiency American Water Works Association 6666 West Quincy Avenue North Carolina Division of Pollution Prevention Denver, CO 80235 USA and Environmental Assistance Phone: (303)-794-7711 P.O. Box 29569 Web site: http://www.awwa.org/ Raleigh, NC 27626-9569 Phone: (800) 763-0136 or (919) 715-6500 Fax: (919) 715-6794 Email: [email protected] Web site: http://www.p2pays.org

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The North Carolina Division of Pollution Prevention and Manufacturing Extension Partnership (NC MEP) Environmental Assistance (DPPEA) provides free, non- Program. The NC MEP team of engineering specialists regulatory on-site pollution prevention assessments, offer technical assistance to North Carolina manufactur- including water efficiency to businesses, industries, and ers such as industrial management, computer applica- municipalities in North Carolina. DPPEA resources also tions, plant engineering, and material handling. Limited include technical fact sheets and manuals on pollution technical assistance, information, and site visits are prevention and a clearinghouse of more than 13,000 provided free of charge. More extensive support and references. A matching grant program is also available consulting are priced according to project length and for innovative pollution prevention and water efficient required resources. technologies. Waste Reduction and Technology Transfer Program North Carolina Division of Water Resources (WRATT) (Water supply assistance, planning, allocation, and Land-of- Sky Regional Council conservation) 25 Heritage Drive Phone: (919) 733-4064 Asheville, NC 28806 Web site: http://www.dwr.ehnr.state.nc.us/home.htm Phone: (828) 251-6622 The Division of Water Resources provides technical The WRATT program provides water efficiency, assistance to water systems with water supply planning, multimedia, and greenlights assessments to busnesses and leak detection, water conservation, and water shortage industries in western North Carolina. The WRATT response planning. program utilizes volunteer engineers and scientists to perform on-site assessments and report recommendations. NCSU’s Industrial Extension Service North Carolina State University North Carolina Cooperative Extension Service College of Engineering North Carolina State University Raleigh, NC 27695 College of Agriculture and Life Sciences Phone: (919) 515-2358 Raleigh, NC 27695 Web site: http://www.ies.ncsu.edu Phone: (919) 515-3173 The North Carolina State University Industrial Also see your local county agents. Extension Service and the North Carolina Energy The Cooperative Extension Service can provide technical Division can provide energy audits and energy conserva- assistance, publications and research about water tion courses for a small fee. This assistance targets nearly efficient landscaping. all basic unit operations of a manufacturing facility ranging from compressors to HVAC units. Contact Jim Parker at (919) 515-5438 for additional information State Government Organizations about energy and related water management issues. North Carolina Division of Water Resources NCSU’s Industrial Assessment Center (Water supply assistance, planning, allocation, and Department of Mechanical and conservation) Aerospace Engineering Phone: (919) 733-4064 Box 7910 Web site: http://www.dwr.ehnr.state.nc.us/ Raleigh, NC 27695-7910 home.htm Phone: (919) 515-1878 Contact: Steve Terry North Carolina Division of Water Quality Another program at North Carolina State University, (Water reuse permitting, wastewater permitting, tax called the Industrial Assessment Center (IAC), provides credits, concentration/mass-based wastewater permit preliminary energy, waste, and water reduction audits issues) free of charge for small and medium-sized industries P.O. Box 29535 within a 150-mile radius of Raleigh. Raleigh NC 27626-0535 Phone: (919) 733-5083 Manufacturing Extension Partnership Web site: http://www.h2o.enr.state.nc.us/ Industrial Extension Service North Carolina State University Phone: (800) 227-0264 Web site: http://www.ies.ncsu.edu/ieswww/ programs/mep/ The Industrial Extension Service at North Carolina State University recently introduced the North Carolina

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North Carolina Division of Pollution Prevention and Environmental Assistance Water Saving Toilet Retrofits (Technical and financial assistance to businesses, Aqua Saver (Water Saving Devices for Gravity industries, and municipalities) Toilets) (800) 723-6954 P.O. Box 29569 Rectorseal Corp (Early Closing Flapper Valves) Raleigh, NC 27626-9569 (800) 231-3354 Phone: (800) 763-0136 or (919) 715-6500 Web site: http://www.p2pays.org Commercial Bathroom Efficiency Bradley Corporation (312) 463-2454 North Carolina Division of Energy Kohler Plumbing (414) 457-4441 N.C. Department of Commerce Chicago Faucet Company (847) 803-5000 P.O. Box 29571 Coyne & Delany Co. (804) 296-0166 Raleigh, NC 27626-0571 Microphor, Inc. (800) 358-8280 Phone: (919) 733-2230 Sloan Valve Company (847) 671-4300

Pressurized Flush Toilet Other Water Resource Information Sloan Valve Flushmate (800) 875-9116

Water Librarian’s home page Foodservice Plumbing http://www.wco.com/~rteeter/waterlib.html T&S Brass and Bronze Works (800) 476-4103 Fisher Manufacturing Company (800) 832-8238 Toilet Information, testing and repair Niagra Conservation (800) 831-8383 http://www.toiletology.com Resources Conservation (800) 243-2862

EPA EnviroSense Foodservice Dishwashers http://www.epa.gov/envirosense/ Champion (910) 661-1979 Hobart Corporation Representative (704) 527-6381

Vendors Spray Nozzles FOGG-IT Nozzle Co. (415) 665-1212 Use local resources first. Many suppliers that a Spraying Systems Co. (704) 392-9448 facility currently uses may represent manufacturers Milton Industries, Inc. (312) 235-9400 of water efficient plumbing hardware, fixtures, controls, treatment, and process equipment. Valve Shut-off (foot controlled) Pedal Valves, Inc. (800) 431-3668 General Domestic/Plumbing T&S Brass and Bronze Works (800) 476-4103 Sloan Valve Co. (800) 580-7141 Zurn Industries (800) 997-3876 Auditing Tools American Standard, Inc. (800) 223-0068 MicroWier Company LLC (503) 235-0792 Delta Faucet Co. (519) 659-3626 Elkay Manufacturing Co. (630) 574-8484 Waterless Composting Toilet Kohler (800) 456-4537 Bio-Sun Systems, Inc. (800) 847-8840 Niboc Inc. (800) 642-5463 Crane Plumbing (847) 570-3566 Cooling Tower & Boiler Water Treatment and Control Gerber Plumbing Fixtures Corp. (847) 675-6570 Marley Cooling Towers (913) 664-7400 Mansfield Plumbing Products (614) 825-0960 Nalco Chemical Co. (708) 305-1000 Eljer Plumbingware (800) 423-5537 Universal-Rundle (800) 955-0316 Vehicle Washing Water Recycle U.S. Brass Inc (800) US-BRASS Sobrite Technologies (309) 467-2335 Other Plumbing contacts: Web site: http:// Earth Care Technologies (360) 697-2376 www.plumbingnet.com/listc.html Custom Applied Technology Corporation (888) 536-7100 Pressure Reducing Valves Waste Water Management, Inc. (561) 747-8028 Watts Regulator Co. (978) 688-1811 Specified Equipment Co. (800) 328-2747 Wilkins (805) 238-7100; Kleer-Flo (800) 328-7942 Cash, A.W. Valve Mfg. (205) 775-8200 N/S Corporation (800) 782-1582

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California Steam (800) 432-7999 California Water Conservation Co. (Water performance, audit, retrofits) Laundry Water Reuse 7277 Hayvenhurst Avenue, Suite B-5 Hydrokinetics (800) 582-5599 Van Nuys, CA 91406 GuestCare, Inc. (214) 243-3035 Phone: (818) 787-5588 Fax: (818) 787-5599 Consultants and Service Providers CTSI Corporation Advanced Conservation Technologies, Inc. (Leak (Water management, audits, retrofits) detection) 2722 Walnut Avenue 13813 Turkey Foot Road Tustin, CA 92780 North Potomac, MD 20878-3935 Phone: (800) 660-8028 Phone: (301) 840-0500 Fax: (714) 669-4309 Fax: (301) 840-0081 Health Consultants American Leak Detection, Inc. (Water management, audit, retrofit, leak detection) (Leak detection) Leak Tec Division 888 Research Dr., Suite 109 122 Space Park Drive Palm Springs, CA 92262 Nashville, TN 37222-4597 Phone: (760) 320-9991 Phone: (800) 769-3394 Fax: (760) 320-1288 Web site: http://www.leakbusters.com John Olaf Nelson Water Resources Management (Performance, audits, retrofits) American Water & Energy Savers 1833 Castle Drive (Water performance) Petaluma, CA 94954 12922 SW 132 Court Phone: (707) 778-8620 Miami, FL 33186 Fax: (707) 778-3566 Phone: (305) 378-8923 Fax: (305) 378-4401 Maddaus Water Management (Water management/performance) Amy Vickers & Associates, Inc. 9 Via Cerrada (Program implementation, audits, retrofits) Alamo, CA 94507 Amherst Office Park Phone: (510) 820-1784 441 West Street, Suite G Fax: (510) 820-2675 Amherst, MA 01002-2967 Phone: (413) 253-1520 Margiloff & Associates Fax: (413) 253-1521 (Water management, audit and retrofits) 621 Royalview Street AquaMetrics (Audits, retrofits) Duarte, CA 91010-1346 1114 Chesterton Avenue Phone: (626) 303-1266 Redwood City, CA 94061-1324 Fax: (626) 303-0127 Phone: (650) 366-8076 Fax: (650) 366-2804 Planning & Management Consultants, Ltd. (Water management, leak detection, audits) ERI Water 6352 South Highway 51 (Leak detection) Carbondale, IL 62903 49 Edge Hill Road Phone: (618) 549-2832 Newton, MA 02167 Fax: (618) 529-3188

Best Management Partners United Energy Associates, Inc. (Water performance, audit, and retrofits) 140 North Orlando Avenue, Suite #150 1704 Elm Street Winter Park, FL 32789 El Cerrito, CA 94530-1909 Phone: (800) 742-3362 Phone: (510) 620-0915 Fax: (407) 740-0169 Fax: (510) 620-0916

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Volt VIEWtech Water Management Services, Inc. (Management, audits, retrofits) (Leak detection) 3430 E. Miraloma Avenue 5677 Oberlin Drive, Suite 110 Anaheim, CA 92806 San Diego, CA 92121 Phone: (619) 573-0105 Phone: (619) 824-0900 Fax: (619) 573-1854 Fax: (619) 824-0901

Water Management, Inc. WaterTech International, Inc. 117 Clermont Avenue (Water management, leak detection) Alexandria, VA 22304 One Kendall Square, Suite 2200 Phone: (703) 370-9070 Cambridge, MA 02139 Fax: (703) 370-9179 Phone: (800) 981-1106 Fax: (781) 592-8005

113 References

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