Conservation Efficiencies: Energy Saving Investigation Process

Energy conservation almost always begins with water conservation, including the process of improved accounting for water losses within the various complex operational systems. What do the icons below mean?

Water Conservation

Encouraging water conservation has a direct linkage with energy conservation. Not only does it save energy resources, it also frees up water that can be used for future uses, reducing the dependence on higher prices involved with source development, including capital costs, water rights costs, or operational costs. Any conservation planning effort should at least look at the following basic strategies and include implementation plans as practical:

• The Plan Develop a comprehensive Water Conservation Plan and review the relationships between water and energy conservations therein.
• Implementation Implement ordinances and rules and regulations which affect the strategies and goals contained in the Conservation Plan.
• Measure Accurately All water use, including separate meters for irrigation and domestic uses, if necessary.
• The Standards Know what the real supply and demands of your water system are. Know what a typical Equivalent Residential Connection (ERC) uses in a year, an average month, and a peak month and day if possible. Use these standards to compare conservation performance over time.
• Price Water to Recognize its Finite Nature Pricing mechanisms should provide incentives to water users who conserve water as well as penalties for those who waste it.
• Hold Responsible All water users for protecting the quality of water resources at their disposal.
• Incentives Create financial or publicity incentives to reward users for efficient irrigation systems. Key elements to observe are system design, operation, and maintenance, combined with effective scheduling and management practices.
• Education Create or assist in educational programs, which emphasize to all water users the absolute necessity of supporting regulatory policies, which reward conservative and efficient water use.
• Reclaim Support water reclamation initiatives if feasible, particularly for irrigation, including the use of reclaimed water from municipal, industrial, and other available sources, where practical.
• Prioritize Water Development Give increased support to developing new water resources, conveyance, and storage facilities, which enhance dependable water supplies for urban and agricultural use, with proper consideration given to legitimate environmental concerns.
• Buy-In Participate in water conservation planning as an ongoing program. These plans must be in place prior to a critical need and must provide for each water user’s acceptance of a fair share of any water conservation effort.
• Manage the Resource Institute studies to identify water use and misuse by all segments of the water using industry to provide data on which to base decisions regarding equitable water distribution during periods of drought or other shortage or water quality event.
• Manage the Peak Investigate innovative water storage projects, to allow the supplier to better manage its water resources during peak periods of the year.
• The Water and Energy Nexus Meld water and energy conservation into a unified strategy. Water and energy share many of the same conservation strategies and should be looked at conjunctively in any conservation program.
• Water Loss Reduction Programs Are very necessary to demonstrate to customers that the water supplier is doing everything possible to minimize water loss on the supply side of the equation while promoting conservation programs to the end users on the demand side.
• Legislative Actions City or county landscape ordinances can save considerable resources when properly applied in the initial project planning and design phases.

Water Accountability

Accounted and unaccounted water losses waste significant energy, resources, and money, and can be at least partially remedied through a regular water audit and thorough investigation using the processes below. Most types of water losses fit into one or more of the following categories. Each system should develop a program to regularly or even continually (using SCADA) investigate, quantify if possible, and mitigate as much water loss as possible. (NOTE: Leak detection instruments may be required in many of the tests needed for this program). The categories of water loss are:

Unbilled Metered Consumption

• This is usually a water revenue loss (if the meter is read) resulting usually from a defect in the accounting and billing systems and controls of the utility (also see Systematic Data Handling Errors).
• This can also be a loss from special agreements, judgments, or other special treatment of customers who are metered (at least making a demand reading usable in a water audit—if read).
• This can also be a water and revenue loss if the meter is NOT read.
• The water utility owned facilities can often fall into this category, i.e., offices, plants, etc.

Unbilled Unmetered Consumption

• This category consists mainly of forgotten customers.
• Often users that are some of the earliest connections which might be forgotten or were believed to be terminated in the billing system but not disconnected.
• Firefighting and other emergency water uses fall into this category.
• Again—often the water utilities own facilities can fall into this category.

Unauthorized Consumption

• This typically involves water theft, illegal users, or connections that have been unauthorized in the past and not disconnected.
• Unauthorized construction water users will often be found here (i.e., a meter by-pass) if not regularly checked up on.

Customer Metering Inaccuracies

These errors result usually from:

• Lack of a meter testing and replacement program.
• Meters that are not designed for the particular application or installation configuration.
• Meters that are too old, obsolete, or are reaching their end of life.
• Meters that are damaged or partially or completely plugged.
• Meters that have failed.
• Meters that have lost their power source (if applicable) or their electronic read system batteries have been depleted.
• Meters damaged or stopped due to freezing conditions.
• Meters that cannot be tested or verified due to their inaccessible conditions, i.e., in the basement or crawlspace of a home, etc.
• Lost meters.
• Vandalized meters or reading equipment.
• Oversized meters, particularly on services where the meter was designed to handle fire flow demands from a fire sprinkling system.

Systematic Data Handling Errors

This category is where errors in data processing occur, namely:

• Clerical data entry errors.
• Meter data configuration errors, i.e., types, size, units billed, zero multiplier units, etc.
• Meters coded to the wrong customers.
• Billing system rate entry and testing errors.
• Errors or “bugs” in the actual firmware of the reading equipment or the software used for reading equipment and billing.
• Errors due to the lack of maintained software updates.
• Lack of an accounting control system to review or check up on billing reports, meter work orders, etc.

Leakage on Distribution System Mains

• Leak detection audits should be performed on a regular schedule, starting with older and less reliable infrastructure.
• The establishment of a system typical water loss baseline, aids in the identification of new leaks as well as performance of you water loss programs.
• Meter performance and testing. A regular testing program should be implemented. Many residential meters have an accuracy curve that drops significantly after 10 to 15 years. As much as a cup per minute or more can pass undetected through some meters. Larger systems should consider purchasing or constructing their own meter testing benches.
• Master metering should be provided where practical when a large user base is fed off of one or two lines, and mass balance tests reviewed regularly (supply in, less the summed user meter demands).
• Fire hydrant leak tests should be performed regularly.
• Operational leaks, i.e., flushing and testing should be metered and accounted for if possible.
• Fire department tests—if unmetered, an estimate should be maintained by the fire department and submitted to the utility.
• Sewer system flushing programs should utilize hydrant meters.
• Construction water should be metered. Investigate the installation of metered bulk water stations if construction water places a regular heavy demand on a system. This can reduce significantly wear and losses on fire hydrants.
• Fire hydrant meters should be tested regularly. They fail or can be damaged fairly easily, especially if used for construction water.
• Can the SCADA system be provisioned to monitor for water losses on a real-time basis?
• Investigate the implementation of automatic PRV pilot adjustment systems which can adjust pressures for high and low demand periods. Lower pressures at low demand periods can reduce water losses on the distribution system.
• Regularly check for water losses at PRV stations and other distribution system regulation valves.
• Air-vac and air release valve stations are an often overlooked source of water losses. Many of these are lost and hidden but can result in significant losses if damaged by freezing or other problems.

Leakage on Service Lines (Laterals)

• If a leak is found on a service line after the meter, due to corrosion or age – there is a very good chance there is a leak on the service line feeding the meter.
• Know where all service line valves are using maps, GPS, GIS, etc. Most of the time these are covered over by the customer.
• If a customer has a fire sprinkling system, does it have a tested flow detection system?
• Know the soil conditions in areas that are prone to leaks.
• Use service line materials and depths which are more suitable to your environment and soil conditions.
• Automated Meter Read systems can aid in the locations of service line leaks by observing trends throughout the night or unoccupied seasons or times. They can also detect leaks from freezes etc.

Leakage on Tanks and Overflows

• Leaks in tanks can be found through regular internal and external inspections.
• On metal tanks, inspect for corrosion and cathodic protection issues. Recoat the tank if necessary.
• Check for leaks in tank control vaults and valve systems, including tank level regulating altitude valves.
• Excessive water overflow and other losses in tanks can be caused or remedied by the following:
  • Proper Placement of Reservoirs and PRVs. Keep pressures feeding an altitude valve at a minimum if possible.
  • If feasible, use PRVs less and reservoirs more for pressure control.
  • Investigate the use of reservoir inlet and outlet detection devices.
  • Investigate reservoir emergency or seismic control valves which close to protect storage in an emergency water loss situation.
  • Investigate reservoir overflow detection systems.
  • Watch for reservoir level transducer failures or improper level calibrations.
  • Ensure that reservoirs are properly vented and protected.

Leakage Within Plants and Equipment

• • Check for leaking pump surge anticipator or pressure relief valves which discharge water to the atmosphere.
  • Check for leaking pump control valves (deep well type) which may discharge water to the atmosphere.
  • Check pumps for excessive leaks in pump seals.
  • Check for leaking air-vac and air release valves in pump stations and treatment plants.
  • Regularly check for water losses at regulation valves including altitude valves, electric and pneumatic actuated valves, pump to waste PCVs, and PRVs.
  • Ensure that filter to waste cycle times are not overly excessive.
  • Investigate the feasibility of backwash water re-use, either internally or for irrigation etc.

• Inspect sedimentation, mixing, clarifier, filter basins, systems and the like regularly for leaks, performance issues, etc.
• Monitor for leaking well foot or other check valves on sources.