Non-Domestic Water Audit Report

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Arline Murphy
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1 A Steak House in Massachusetts INTRODUCTION The Massachusetts Water Resources Authority (MWRA) has developed a program to audit the water use of some of its largest commercial, industrial and institutional users as part of its mission to preserve the supply of fresh water to the Metropolitan Boston area. The purpose of this program is to identify cost effective water saving measures and encourage conservation among those users. Pequod Associates, Inc. is a consulting engineering firm under contract to MWRA to conduct those audits and assist users in implementing the savings measures recommended. This report, prepared by B&M Technological Services, Inc. (B&M) under subcontract to Pequod, documents a water audit conducted for a Steak House in Massachusetts. Our report, which specifically addresses the Restaurant at Main Street and the New Addition at Cross-Street contains a description of each building, the work conducted there, its historical water use and an inventory of water using equipment. Following those descriptions are the measures we recommend for implementation or further study, with cost and savings estimates. B&M and a representative of MWRA will meet with the Restaurant operations staff shortly after this report has been delivered to discuss the findings and recommendations. EXECUTIVE SUMMARY From August 27, 1988 to August 28, 1989, the Restaurant consumed 13.2 million gallons of water at a cost of $61,591. The resaurant which underwent reconstruction, was re-opened for business on April 1, Billings as of August 28, 1989 indicate a consumption of. 6 million gallons of water at a cost of $2,665 for the six month period. Assuming consumption remains the same, the projected annual usage is 1.2 million gallons of water at a cost of $5,330. Water consumption at the Restaurant is minimal for a facility of this type (it is new and uses state-of-the-art equipment). Water is used at a few wash sinks, two toilets, baking processes and floor and rack washing. The Steak House 3/90 -l-

2 The following table summarizes the measures we found to be cost effective at the Restaurant. They represent a water savings of 7.2 million gallons per year, or 55% of present consumption. We recommend that the Restaurant implement all of these measures. Measure Irrigation Condenser Water Loop Toilet Retrofit TOTAL PROFILES Building Gallons cost Savings Payback 849,500 $ 1,250 $ 3, yrs 5,356,OOO $27,000 $25, yrs 693,000 $ 418 $ 3, yrs ,898,500 $28,668 $32, yrs The Restaurant, which was constructed in 1951 and 1975, is a two story building with a full basement. This building comprises approximately 70,000 sq.ft. Facility The Restaurant operates 7 days per week, 52 weeks per year. The Restaurant is open to customers from 11:OO a.m. to 11:OO p.m. Monday through Sunday, except for Friday when it opens at 10:00 a.m. According to plant personnel, approximately 40,000 meals are served per week, with the highest volume occurring Thursday through Sunday. The occupancy schedule is as follows: Cooks 7:00 a.m. to 3:00 p.m. Dishwasher 9:00 a.m. to 5:00 p.m. Customers 11:OO a.m. to 11:OO p.m. Customers (Friday only) 10:00 a.m. to 11:OO p.m. Cleaning Crew 11:OO p.m. to 7:00 a.m. Planned shutdowns occur on Thanksgiving and Christmas. For the remaining holidays, the Restaurant is only open for dinner. Although expenses are a concern, management has not limited their consideration of measures to those with payback periods of two years or less. Water consumption was reduced in 1988 by the replacement of once-through cooling with a closed loop system for two refrigeration units. Water consumption in the Steak House was kept to a minimum by using closed loop cooling for all refrigeration equipment and lobster tanks, as well as through the use of high pressure water guns for floor and rack cleaning. The Steak House Inc., 3/90-2-

3 Water Water is purchased from the Town and supplied through two meters. The main feed is a 3 inch diameter supply at 70 psi from Street. A 2 inch diameter supply at about 60 psi from Route 1 is maintained as a backup. The water meter is located down stream of these connections. Incoming water is sent through a sand filter and distributed at 60 psi to the building. The meter is read twice annually and billed shortly thereafter. MWRA supplies water to this facility at a graduated rate as outlined below. Sewage effluent is not metered. The sewer charge is based on the water readings. The sewage leaving the building passes through a 1,000 gallon grease trap. (See Appendix A for water bills for the period of 02/01/89 to 08/28/89. Usage for 08/29/88 through 01/31/89 was obtained by phone from the Town : Tax Collector.) The average combined water and sewer rate is $4.67 per thousand gallons. This rate will be used for the purpose of calculations in this report. Water is used for the following: o Plumbing: Inlet water sand filter back wash; faucets, toilets and urinals in washrooms. o HVAC : Hot water heating make-up. o Process: Kitchen - dishwashing, rack washing, coffee makers, lobster defrosting basins,. pot washing sinks and cooking. Bar and Restaurant - water fountains, sinks and ice makers. Support - refrigeration condenser cooling, ice makers condenser cooling, pot heater steam make-up (100% return) and refrigeration condenser closed loop cooling make-up. Other - lawn irrigation. The Steak House 3/90-3-

4 Estimated Usage (gal/yr): Sand Filter Backwash 19,500 Toilets 3,120,000 Faucets 693,000 Water Served 145,000 Coffee Served 145,000 Dishwasher (2 units) 1,045,000 Glasswasher 65,000 Rack Cleaning Pressure Gun 147,000 Pot Washing Sink 153,000 Condenser Cooling: (3) refrig. comp. 4,591,000 (2) ice makers 765,000 Lawn Irrigation 1,744,000 Remaining: Boiler And Refrigeration 552,500 Makeup, Lobster Defrost, Etc. TOTAL* * The above calculations are based on: 13,185,000 gal/year 1. Building and Equipment survey. 2. Manufacturers literature. 3. Field measurements of pipe sizes, temperatures and flow rates. 4. Information supplied by facility personnel. Electricity Electricity is purchased from Massachusetts Electric Company at Rate G-3. The average cost per kwh is $0.063, which is based on dividing the total charge of a recent bill by the number of kwh used. (See Appendix B.) Natural Gas Natural gas is used to generate heat for domestic hot water, hot water heating and steam for kitchen and bakery needs. The -Steak House Inc., 3/90-4-

5 WATER CONSERVATION MEASURES IRRIGATION Discussion The lawn irrigation system is divided into three zones with a total of 15 dispersion heads. The system is operated by a time clock with each zone delivering water for one hour twice per day. Water pressure at the head outlet is an estimated 50 psig with a resulting flow rate of 3.46 gpm. By reducing the pressure to 15 psig, the flow will be reduced to 1.81 gpm. According to the manufacturer, excess pressure does not contribute to useful coverage, but rather causes excessive drift. Therefore, pressure reduction will improve the irrigation effectiveness. Recommendation A typical lawn requires approximately 1 inch of water per week from either rain or irrigation. Therefore, irrigation is not required when it rains. A moisture sensor can be installed in the ground to detect the sufficiency of water in the soil, override the timeclock and, if necessary, prevent irrigation from occurring for that cycle. Implementation Reduce water pressure by adding a pressure reducing valve (PRV) on the 2 inch supply line. Add a moisture limiting switch to override the time clock when watering is not required. Savings Pressure reduction: 7 mo/yr x 30 day/mo x 2 time/day x 1 hr/time x 15 heads x ( ) gpm/head x 60 min/hr = 623,700 gal/yr Moisture high limit controller: 7 mo/yr x 30 day/mo x 2 hr/day x 0.33 (div.factor) x 15 heads x 1.81 gpm/head x 60 min/hr = 225,800 gal/yr Total Savings: 849,500 gal/yr x $4.67/1,000 gal = $3,970/yr The Steak House Inc., 3/90-5-

6 The estimated cost to purchase and install a 2 inch water regulator is $800 and 3 moisture controllers (one for each zone) is $450. Payback: ($800 + $450) / $3,970 = 0.3 years The Steak House Inc., 3/90-6-

7 CONDENSER CLOSED LOOP COOLING Discussion City water is used for non-contact condenser cooling of three refrigeration compressors and two ice makers and is discharged to the sewer. The three refrigeration units are rated at 36 amp, 200 volts each and the average water temperature rise is l0 o F. The two ice makers are rated at 13 amp, 200 volts each and the average water temperature rise is 15 o F. Because the refrigerators are constantly opened and closed when the restaurant is serving customers, we are using a higher than normal diversity factor of.66. Annual water consumption is as follows: Refrigeration: Q = 36 amp x 200 volt x 3.14 = 22,600 Btu/hr flow = 22,600 Btu/hr / (500 x l0 o F) = 4.52 gpm Usage = 3 units x 4.52 gpm/unit x 60 min/hr x 0.66 (div.factor) x 24 hr/day x 365 day/yr = 4,591,OOO gal/yr Ice makers: Q = 13 amp x 200 volt x 3.14 = 8,250 Btu/hr flow = 8,250 Btu/hr / (500 x 15 o F) = 1.1 gpm Usage = 2 units x 1.1 gpm/unit x 60 min/hr x 0.66 (div.factor) x 24 hr/day x 365 day/yr = 765,000 gal/yr Recommendation We recommend providing a closed loop cooling system for heat rejection. Implementation Provide a closed water cooling system consisting of a fluid cooler, located on the roof, in-line circulating pump and distribution piping. The existing water cooling will remain in place and isolated with shut-off valves for stand-by operation. T h e Steak House Inc., 3/90-7-

8 Savings Savings: 4,591,OOO + 765,000 = 5,356,OOO gal/yr 5,356,OOO gal/yr x $4.67/1,000 gal = $25,OOO/yr cost: Design & Engineering Roofing Electrical Power And Controls Equipment (Cooling Tower and Pumping) Piping and Accessories TOTAL Payback: $27,000 / $25,000/yr = 1.1 years $ 6,000 3,500 4,000 4,500 9, $27,000 The Steak House Inc., 3/90-8 -

9 FLUSHOMETER RETROFIT KIT Discussion There are 19 wall-mounted toilets located throughout the building that are presently fitted with Sloan flushometer valves. Recommendation We recommend that Sloan Flushometer conservation kits be installed in all 19 wall-mounted toilets to reduce consumption by 1 gallon per flush. Implementation The kits can be purchased at a cost of $18 each. Estimated installation time by in-house plumbers is 15 minutes per valve retrofit. At a labor cost of $15/hour, the total cost for this measure is about $22 per retrofit installation. Savings Savings: The facility has estimated that they serve 40,000 guests per week. We estimate that one-third of these people flush the toilet per visit. Sloan Flushometer retrofit kits can be installed to save 1 gallon per flush. Savings are calculated as follows: 1 gal/flush x 40,000 guest/wk x l/3 (div) x 52 wk/yr = 693,000 gal/yr 693,000 gal/yr x $4.67/1,000 gal = $3,24O/Yr cost: $22/unit x 19 units = $418 Payback: $418 / $3,240/yr = 0.1 years The Steak House Inc., 3/90-9-

2016 Plumbing Supplemental Plan Review List

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