Vol. 6, No. 2 - June 1997

Index this issue . . .

• Water Efficiency -
  • North Carolina's Water Supply: A Case for Water Efficiency
  • Water Efficiency: Sizing Up Your Facility
  • Water Efficiency: Cooling Towers
  • Water Resources on the Internet ...
  • One Water Utility's Approach ...
  • Efficiencies in Facility Domestic Water Use Offer Cost Savings Potential
  • Landscape Irrigation
  • Water Efficiency Case Studies
    • Safelite Glass Company, Enfield, NC
    • Craftsman Fabrics Industries, Inc., Concord, NC

• Multimedia News Update
  • Water Quality News
  • Air Quality News
  • Solid Waste News
  • Hazardous Waste News
  • Compliance Tips for Small Businesses

• Calendar of Events

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North Carolina's Water Supply: A Case for Water Efficiency

Water supplies in many areas of North Carolina are in serious jeopardy. For example, underground water supply reservoirs in eastern North Carolina are dropping by as much as eight feet a year, land surfaces are settling as water is withdrawn, and the potential exists for salt water intrusion into underground drinking water supplies. In the Piedmont area, nearly all available supplies from surface water reservoirs are currently allocated to municipalities. And across North Carolina, the potential for water shortages is increasingly likely.

NC Usage

According to the University of North Carolina Water Resources Research Institute, approximately 4 million North Carolinians rely on groundwater (aquifers) for their daily water supply, and approximately 3.2 million rely on surface water (rivers and lakes). At an average daily consumption of 60 gallons per person, approximately 240 million gallons of groundwater and 192 million gallons of surface water are withdrawn daily for residential uses. The United States Geological Survey estimated that North Carolina industrial and commercial sectors used 332 million gallons per day from publicly supplied sources in 1995. In addition to these uses, the state's water balance also includes minimum quantities of water required to sustain aquatic life in our rivers and streams - of utmost importance to the state's fishing industry, tourism, recreation, and quality of life.

Local and State Response

In response to increased water supply demands and to extend raw water supplies and reduce potential drought periods that are beginning to plague North Carolina areas, several municipalities and water/sewer districts have implemented water efficiency programs. Table 1 lists substantial benefits that can be achieved through these programs.

Water use rate structures can greatly influence efficiency efforts. Trends over the past 10 years show many municipalities moving away from traditional "declining block" rate structures in which the more water users consume, the less they pay. Alternative rate structures such as "uniform" and "inverted block" make efficiency measures more economically advantageous, although almost 52 percent of large municipalities still use declining block rate structures.

Coordinated Efficiency Efforts

Efficiency efforts need to be coordinated among the municipalities and districts that share a river basin and aquifers. North Carolina has been taking steps to improve the accountability and coordination of water use in the state. In 1989, the General Assembly passed a bill that addresses local and state water supply planning. Several bills and rules related to water management have been and are being passed. They include the reuse of reclaimed wastewater (FOCUS, Fall 1996), water supply watershed protection, the Water Use Act, the Coastal Area Management Act, and Basinwide Water Quality Planning.

This edition of FOCUS provides guidance and examples on the sound water efficiency practices businesses and industries can use to support the state's water management efforts.

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Water Efficiency: Sizing Up Your Facility

Water efficiency measures implemented by industrial and commercial facilities can be cost effective as well as environmentally sustainable. Some of the reasons to use water efficiently include preservation of quality water supplies; cost savings in water, sewer, chemical treatment, and energy; expansion of production without increased water use; and delay in the need for new water supplies.

In sizing up the efforts your facility is making in water efficiency, consider the following questions and suggestions for establishing a water efficiency program.

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Water Efficiency: Cooling Towers

It is not uncommon for cooling towers to consume 20 to 30 percent of the water supplied to commercial and industrial facilities. Water savings can be achieved by reducing blowdown or water discharges from cooling towers. Consider the following water-saving suggestions:

• Install an automatic control to shut off the unit when facility is unoccupied (night or weekend hours) or to operate it concurrently with chillers.
• Inspect drift losses. If excessive, install drift eliminators or repair existing equipment.
• Improve operation:
  • Install flowmeters on make-up and bleed-off lines to verify that the tower is operating within specified limits. Meters that display instantaneous flow will be very useful.
  • Operate bleed-off valve on a continuous basis to prevent wide fluctuations in conductivity, which typically cause the average conductivity to be much lower than the desired value. Continuous bleed-off maintains the conductivity of the tower; reduces the chemical requirements; eliminates the possibility that water will exceed the preset, conductivity high value; and conserves water.
• Consider adding sulfuric acid to control scale build up. Sulfuric acid lowers the pH and effectively converts a portion of calcium bicarbonate, the primary cause of scale, to the more soluble calcium sulfate.
• Implement a sidestream filtration system to remove sediment. These systems are useful for high turbidity supply water, airborne contaminants (e.g., oils, dust), or small passages that could clog. Filters are usually rapid sand filters or high-efficiency cartridge filters.
• Replace chemical treatments with an ozonation system, which can cause a five-fold reduction in bleed-off. Ozone treatments control scale (by reacting with mineral ions to form mineral oxides that can be precipitated in the basin or filtered) and viruses and bacteria (by killing the microbes).
• Reuse water from other areas in the facility as make-up water. For example, reuse (1) water from a once-through cooling system, (2) pretreated effluent from other processes (chemicals must be compatible with cooling tower system), or (3) high-quality municipal wastewater effluent.

The table below outlines advantages and disadvantages of options to optimize cooling tower operations.

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Water Resources on the Internet . . .

• NC Division of Water Quality
• NC Division of Water Resources
• WaterWiser - Water Efficiency Clearinghouse A discussion forum.
• The Water Librarian's Home Page Links to many other sites related to water.
• Toiletology 101 Information on how toilets work, how to test for leaks, valve replacement, etc.

Other Resources on the Internet . . .

• VendInfo Over 1,400 vendors of equipment that can be used for pollution prevention. The database can be searched by process (e.g., metal cleaning) or equipment type (e.g., air filters).
• TechInfo Bibliographic database with over 14,000 listings of pollution prevention references, is searchable by subject, title, or author and includes a brief abstract and the location of the work.
• Pollution Prevention List Servers Information on P2Tech and other pollution prevention list servers, links to previous P2Tech discussions, as well as subscriber information.
• TechInfo Listserve A free listserver for the discussion of pollution prevention. Topics range from industrial process technologies to educational materials for schools. Subscribers can post questions or respond to questions with any e-mail software. All correspondence is e-mailed to the subscribers. To subscribe: Send a message, indicating your wish to subscribe and include name and company/organization.

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Efficiencies in Facility Domestic Water Use Offer Cost Savings Potential

Often overlooked at commercial and industrial (C/I) facilities is domestic water use and the potential for significant cost savings through efficiency. Water efficiency measures should begin with the highest water use operations such as cooling, cleaning, rinsing, heating.

Easy improvements in domestic water fixtures such as commodes, faucets, and showers are often overlooked. The quantity of domestic water use at C/I facilities may range from a small percentage at a food processing industry to over 50 percent in an office setting (Figure 1).
Average daily domestic demands in C/I settings range between 20 and 35 gallons per day (gpd) per employee, but savings of 25 to 30 percent are readily achievable.
A facility's assessment of domestic water use should start with the location and repair of any leaks. Pressures in the fixtures also should be checked. A leaky toilet can waste more than 50 gpd; a dripping faucet can waste 75 to 1,000 gallons per week. Outdated fixtures should be evaluated. Faucet aerators and low-flow showerheads will provide payback in less than 3 and 6 months, respectively.
Replacing a 3.5-gpf toilet with a moderately priced 1.6-gpf unit will provide a payback of 1.5 to 3.5 years (Figure 2).	Based on a commercial water and sewer rate of $3.97/1000 gallons and 3 flushes per employee per shift.

Table 1 lists sound water efficiency choices for domestic fixtures.

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Landscape Irrigation

Consider the following ideas to reduce the amount of water required for landscape irrigation.

• Use recycled water for decorative ponds, fountains, etc., and shut water off whenever possible to reduce evaporation.
• Place sprinklers so that only landscape - not walkways or parking lots - is watered.
• Install an irrigation system with controls or sensors to avoid unnecessary irrigation events.
• To provide water directly to the turf roots, use a trickle or subsurface drip irrigation system that is installed underground.
• Implement xeriscaping techniques. Xeriscaping is a comprehensive water management approach to landscaping that considers the type of plants, growth and maintenance patterns, and their interaction with the climate and soil. The following techniques are included in xeriscaping:
  • Practice good landscape design. Good design is the basis of xeriscaping. Factors to consider are directional orientation, which affects sun exposure; existing shade areas, which can be 20 degrees cooler than sunny spots; existing plants, trees, etc.; and nonpermeable areas that contribute to run off.
  • Analyze and improve soil. Your local soil or agricultural extension office can analyze your soil and suggest methods to improve its ability to support plants and retain water.
  • Choose appropriate plants. Indigenous plants may require less water than plants imported from other areas. The low water demand, low maintenance, and pest tolerant features of xeriscaping plants can save your facility money, water, and labor.
  • Establish practical turf (grass) areas. Place turf where it will be most functional, and select the turf that will work best for the particular area. When cutting turf, alternate between a high cut and a low cut. This technique will reduce water use by up to 30 percent without dramatically affecting clipping yields.
  • Water efficiently. Most lawns and plants require only about 1 inch of water per week when growing. Water only in the morning or at night to reduce evaporation losses. Water deeply once a week instead of lightly every day.
  • Use mulch. Organic, non-matting mulch such as assorted barks and leaves is a good ground cover that requires no water and little maintenance. Place mulch around bases of plants, trees, and shrubs to improve the soil, reduce water evaporation, encourage root growth, and improve water penetration.
  • Practice appropriate maintenance. Prune plants and trees only when necessary. Heavy pruning accelerates growth and increases the need for water. Do not cut grass to less than one-third its original height.

The following are among the many benefits xeriscape landscaping provides:

• Reduced water use;
• Decreased energy use (because less pumping and treatment are required);
• Reduced heating and cooling costs (because trees are carefully placed); reduced stormwater runoff; fewer yard wastes; and lower labor and maintenance costs.

Source: Water Management: A Comprehensive Approach for Facility Managers. Enviro-Management & Research, Inc.

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Water Efficiency Case Studies

Safelite Glass Company, Enfield, NC

Safelite Glass manufactures windshields for the automotive industry. In order to reduce or eliminate its monitoring requirements and compliance concerns associated with its NPDES direct wastewater discharge permit, Safelite evaluated its operations and identified several major sources of wastewater. The major sources included three water-cooled air compressors, cooling water for the autoclave and hydraulic fluid, and rinse waters for the glass cutting process. As a result of this evaluation, the facility implemented the following projects.

The volume of wastewater now discharged is less than the EPA threshold that requires pollutant analysis. Although some of these activities required a high capital cost, the elimination of monitoring requirements and compliance concerns and reductions in tap water fees provided Safelite the incentive to implement the projects.

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Craftsman Fabrics Industries, Inc., Concord, NC

Craftsman Fabrics dyes or bleaches and then finishes cloth for knit goods manufacturers. Like many textile dyehouses, Craftsman used to dye various loads with the same volume of water and chemicals, regardless of the size. Although formulating dyebaths was easy with this method, more chemicals and water were often used than were required to properly process the fabric. To reduce water and chemical consumption and wastewater pollutants, Craftsman implemented the following modifications to the dyehouse operation:

• Installed flow meters and differential pressure transmitters on the existing dye machines.
• Modified dyehouse computer software.
• Purchased new dye machinery with the flow metering and pressure differential capabilities already installed.

Craftsman now uses less water and fewer chemicals per pound of fabric by varying the fill levels according to the machine used, size of load, and type of fabric. Thus, for an approximate capital cost of $42,000, Craftsman now saves annually approximately $170,000 in reduced water and chemical costs and increased production output. The company has also reduced wastewater use by an estimated 14 million gallons and chemical use by 0.9 million pounds annually.

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Multimedia News Update

Water Quality News

Mass-Based Limits

While water conservation provides many benefits, a successful program can have a negative effect on wastewater compliance. Because the amount of dilution water is decreased, water conservation will increase the concentration of pollutants in the wastewater for facilities with concentration-based permit limits, mg/L. Thus, a facility may be out of compliance under the concentration-based limit although the facility is discharging the same mass of pollutants, lbs/day.

One effective solution to the problem is to implement a chemical conservation program or other reduction techniques for those chemicals that end up in the wastewater. A second solution is to work with the local water authority to switch concentration-based limits, mg/L, to mass based limits, lbs/day. Many companies have already successfully switched their limits to mass-based.

To determine the mass of pollutants discharged in the wastewater, the facility will need an effluent flow meter to record the daily wastewater flow. The flow, along with the effluent analysis, is used to determine the actual pounds of pollutant discharged. Although there is a capital investment for the flow meter, the cost of the meter is typically paid back quickly in reduced sewer fees for facilities with evaporative losses.

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Air Quality News

Division Initiates Ozone Action Days

Ground-level ozone, the major component of smog, is produced primarily from industrial activities and gasoline burning vehicles. Ground-level ozone is harmful to humans, especially the young, elderly, and individuals with respiratory illnesses. Urban and surrounding areas that are heavily industrialized and populated typically have the highest ozone concentrations and are the most regulated.

With the potential onset of more stringent air quality standards for ozone, the North Carolina Division of Air Quality (DAQ) has recently created the NC Air Awareness Program. The education and outreach components of the program will inform the general public, business/industry, and school children about air pollution, its causes and effects and prevention techniques. When the potential exists for the ozone standards to be exceeded, DAQ will announce Ozone Action Days through newspapers, television, radio, and local employers. To help reduce the number of vehicles driven on those days, DAQ encourages car pooling, telecommuting, and eating in at lunch time, whenever possible. For further information on NC Air Awareness, call 1-888-RU4NCAIR.

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Solid Waste News

Recycled Materials Replace Virgin Materials

North Carolina industries use an impressive variety of recycled feedstock - from common post-consumer materials such as paper fiber to post-industrial materials such as chemicals and textiles. Manufacturers may choose to incorporate recycled materials into their processes because of cost savings, locally available raw materials, the environmental benefits, and customer demand. In a recent survey of North Carolina plastic manufacturers conducted by the NC Recycling Business Assistance Center (RBAC), 91 percent of the respondents cited cost savings in raw material purchases as a major reason the company uses recycled feedstock. And although the survey identified quality concerns as a barrier to the use of recycled feedstock, some companies reported that recycled feedstock improves their product quality.

North Carolina companies should evaluate their feedstock use to determine if opportunities exist to incorporate recycled material into their processes and if such a change could improve their competitiveness. For additional information on this topic, contact the RBAC at (919) 715-6500.

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Hazardous Waste News

Management of Oil Absorbents

The NC Division of Waste Management policy bans absorbents containing oil from North Carolina solid waste landfills. However, the Division does not ban absorbents used to clean up incidental spills of petroleum products such as small volume leaks or spills at service stations, auto dealers, and garages that can be readily cleaned up. Larger volumes of absorbents should be handled through waste oil dealers or hazardous waste service companies.

Here are tips to prevent or reduce the generation of waste absorbents:

• Use drip pans,
• Keep lids closed on containers to prevent spills, and
• Consider reusable or microbial absorbents.

One company that provides an oil absorbent mat or sock rental service picks up the used mats and extracts the oil at its plant. The mats are then laundered and reused.

Contact the Hazardous Waste Section at (919) 733-2178 or the DPPEA at (919) 715-6500 for more information on absorbent management or alternatives.

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Compliance Tips for Small Businesses

Air Emissions Inventory Due June 30, 1997

All air permit holders are required to report their "1996 North Carolina Air Emissions Inventory" to the applicable regional Air Quality Office by June 30, 1997. Pollutants subject to the reporting are the criteria pollutants, North Carolina toxic air pollutants, and federal hazardous air pollutants as listed in the 1990 Clean Air Act Amendments.

To obtain an accurate emissions figure, look at processes, products, and quality of products used over the last year, as well as Material Safety Data Sheets. The Division of Air Quality has spreadsheets for a number of processes (e.g., sawmills, boilers, furnaces) and can assist with locating emission factors, if needed.

If you need assistance or have questions, contact your regional air quality staff or the Office of the Small Business Ombudsman at 1-800-829-4841. This Office provides free, confidential, technical environmental assistance to small businesses.

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Calendar of Events

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The North Carolina Division of Pollution Prevention and Environmental Assistance provides free, non-regulatory technical assistance and training to eliminate, reduce, or recycle wastes before they become pollutants or require disposal. For additional information about any of your waste reduction concerns, contact DPPEA at (919) 715-6500 or 800-763-0136 or e-mail nowaste@p2pays.org.

DPPEA-97-30. June 1997