University Water Conservation Audit
 

Christopher Neuman
Hannah Campbell
Cara Frisbie
Shalini Jain
 

ENVI 490 Water Conservation Group - April 15, 1998
 

Abstract

 Water usage and conservation efforts at Rice University were analyzed to assess current trends and pinpoint areas for future improvement. Data was obtained through personal communications with administrators and engineers, analysis of past water records, a survey of resident students, and field tests of plumbing fixtures and water quality. This information showed Rice has already taken effective steps to increase water efficiency, but further improvements can still be made to conserve water and save money. Replacing current shower heads and toilets with more efficient fixtures is estimated to save the university $64,921 per year after two years. Water recycling systems (graywater recovery, condensate recovery, etc) offer more innovative solutions to water conservation problems and are promising avenues for future research.
 

Introduction
 

 As part of ENVI 490, our group set out to analyze water consumption and conservation on the campus of Rice University. Early efforts at water conservation in the United States started in the 1970's with the development of more efficient plumbing fixtures. Since that time, new technologies have drastically improved and are now readily available to consumers. Recent government acts mandate that manufacturers only produce hardware that meets certain low flow guidelines. Currently, the inclusion of low flow fixtures in kitchens and bathrooms is required by law in all new residential and commercial construction (Fagen 43). In addition, conservation efforts have significant environmental and economic benefits. The added cost of water conserving fixtures is often recovered through savings within a few years.

 University campuses are excellent systems for conservation analysis due to their moderate sizes and relatively isolated conditions. Many campus wide audits have already been conducted and have paved the way for environmentally conscious development. Rice is currently planning for future expansion; therefore, it is timely for Rice to undergo an environmental audit. By examining various aspects of water usage on the campus, we are hoping to identify potential areas for sustainable development. Our analysis includes economic as well as environmental considerations, as it is important that the costs of conservation oriented improvements not outweigh the benefits.
 

 In order to gain a comprehensive understanding of water usage and consumption on the Rice campus, we utilized a multitude of information sources. Specifically, we obtained water usage and billing records, conducted a student survey regarding individual water usage, tested and analyzed various residential plumbing equipment and investigated residue which appeared to impede equipment performance.

Methods

Water Records

 Our primary method of obtaining information regarding water consumption and conservation was through dialogues and interactions with members of the Facilities and Engineering and Food and Housing staff. Through these channels, we obtained Rice University's official water records including meter records and water rates in dollars per gallon. We also learned of several water conservation plans currently being proposed or implemented on campus.
 

Survey

 We developed a survey to investigate overall water usage by resident undergraduate students. This was done with the help of Leona Urbish, Director of the Office of Institutional Research at Rice. The survey contained eleyen to fourteen questions, depending on gender, pertaining to time utilized for water consuming activities. The activities chosen were those deemed most common and the easiest habits to change for water conservation efforts. We sent the survey to a randomly selected group of 356 students living on campus over the electronic mail system.
 

Flow Rate Field Study

 By speaking with Joe Lopez, Plumbing Supervisor at Rice, we learned that each residential college is equipped with low flow shower heads (3/30/98). We then conducted a field study of the faucets and low flow shower heads in each of the residential colleges to gauge the efficiency of this equipment. Flow rates were obtained by measuring the amount of water flowing from the shower heads at the maximum rate over a period of thirty seconds. Water was collected in a large basin and aliquotted into a one liter graduated container. We tested faucet flow by measuring the time necessary to collect a liter of water in a graduated container at the maximum rate of flow.
 

Unknown Deposit Identification

 During the flow rate study we observed a hard residue that appeared to impede the optimal flow of water from the shower heads. As a result we soaked several different shower heads in a sulfamic acid solution, with the notion that the deposits might be calcium carbonate (CaCO3). We also presented a deposit-laden sample to Greg Dulaney, Rice's Central Plant Engineer. This sample was immersed in hydrochloric acid in an attempt to determine the nature of the deposits. Consequentially, James Muiioz, Rice University Mechanical Engineer, offered to test the campus water for CaCO3 content (hardness).

Data
 

Water Records

 The water records, obtained from James Mufioz, were organized in a spreadsheet format compiled by the Department of Facilities and Engineering. According to this spreadsheet, the following buildings operate from individual meters and only receive water from the City of Houston: Autry Court, Rice Stadium, Rice University Police Department Building, Alice Pratt Brown Hall, Center for Nanoscience Technology, and the James Baker Institute. There are also three irrigation meters which receive only city water. The rest of the buildings on campus receive a variable mixture of city water and water from the Rice well. These buildings do not have individual meters, and their water intake is not individually monitored. The city water is sold to Rice at a rate of $2.22 per thousand gallons, and Rice is charged $3.72 per thousand gallons for waste water treatment. All water consumed on campus is subject to the waste water treatment charge, except water used for irrigation. The City of Houston only allows Rice to use fifty thousand gallons (190,000 liters) of Rice well water per year due to subsidence concerns.

Flow Rate Field Study
Table 1: Data from flow rate testing of residential bathrooms

College (room #)	Shower flow rate (L/min)	Faucet flow rate (L/min)
Lovett(118)	4.5	4.2
Lovett(218)	8.3	10.0
Baker (252)	8.0	7.3
Will Rice (232)	8.0	7.3
Jones (222)	8.0	16.7
Brown (2nd floor)	13.6	10.0
Hanszen (262)	8.5	7.2
Weiss (332)	7.0	6.7
SidRich(551)	6.6	7.5
Average	8.1	8.5

Survey

 We sent out 356 surveys to on-campus undergraduate students and received 130 responses, resulting in a response rate of 37%. The information presented in the following, charts was derived from water records and survey data.

Table 2: Comparison of water consumption and costs for regular versus low flow toilets

	Regular flow toilets	Low flow toilets
Liters per flush	17.0	13.3
Liters used per month	4,472,868	3,480,065
Water cost per month ($)	2623.2	2040.9
Wastewater cost per month ($)	4395.6	3419.9
Total cost per year ($)	84225.6	65529.6

Table 3: Comparison of water consumption and costs for current versus updated shower heads

	Current hardware	Updated hardware
L/min	8.5	4.6
Liters used per month	5,321,380	2,866,503
Water cost per month ($)	3120.8	1681.1
Wastewater cost per month ($)	5229.4	2817.0
Total cost per year ($)	100202.4	53977.2

Unknown Deposit Identification

 Upon treatment both sulfamic acid and hydrochloric acid the unknown deposits on the shower heads began to dissolve. In addition, Mufioz tested both city and well water for hardness due to Ca. These tests detected 112 ppm CaCO3 in the city water and 38 ppm in the well water (Mufioz 4/13/98).

Analysis
 

Water Records

 The water records were used mainly to create a cost benefit analysis of low flow equipment. We coupled payment rates of city water and waste water with survey information to determine how decreased water usage can save the university money. It is apparent after observing three years of water records that there is a downward trend in water consumption. This translates into more buildings using less water, which leads us to believe that water conservation is increasing on campus. Due to the organization of the water records, it was difficult to pinpoint the specific areas where water conservation efforts have made substantial differences and where further improvements would be most beneficial. We therefore focused our research on understanding personal water consumption habits.

Flow Rate Field Study

 All of the showers in the residential colleges are equipped with low flow heads. The ones that we observed were low flow and functioning properly, except one that had a slightly higher flow rate. There were large variations in observed faucet maximum flow rates. It is apparent that people do not often use them at maximum capacity since the pressure and amount of water discharged using the maximum flow is far too extreme for regular usage.

Survey

 By surveying a random cross section of resident undergraduates we estimated campus-wide personal water consumption for certain activities. From our knowledge of payment rates and our estimate of residential toilet usage, low flow toilets will save the university $18,696 per year. It would cost the university approximately $23,300 to retrofit the 466 toilets with low flow flush valves in the residential colleges (Valentine 4/14/98). This translates into a complete return on investment in less than 2 years, at which point the university will save money from lower water and wastewater charges.

 A similar analysis was used to compare the standard "Baby Chatham" shower head with the "Niagra Conservation" shower head being tested in one residential college bathroom. From the survey we estimated the total time resident undergraduates spend showering. Using the average shower flow rate from our field study and payment rates from the water records we estimated the amount of money spent on showering per year. Following the same procedures with the updated model, we determined a savings of $46,225 per year.

Unknown Deposit Identification

 The data obtained from the hardness testing clearly indicates that the well water is softer than the city water and Rice therefore benefits from using a mixture of well and city water. This enables the low-flow equipment to function more efficiently and extends the life of the shower head since it is less likely to become clogged. Even though all of the observed shower heads had significant CaCO3 deposits most shower flow rates were still within the low flow rate boundaries. Furthermore, removing the deposits from the shower heads did not noticeably change the flow rates, but did improve the spray of the water.

Conclusions

 After extensive research, we believe Rice university has shown considerable interest in adopting practices which conserve water. The implementation of low flow shower heads has been successful, however, more efficient fixtures are available. These updated models should be considered for future construction and the replacement of worn out or broken fixtures. It is unlikely that a full retrofit at this time will provide substantial savings for the university. Contrary to our initial hypothesis, the CaCO3 deposits found on the shower heads do not appear to affect their low flow capacity. Although removing the residue improved the spray, the difference does not warrant the cost of routine cleaning. The best way to attack this problem is by softening the water supply; however, this is extremely costly. Therefore, the combination of well and city water makes the water less hard and helps preserve the plumbing fixtures.

 The second major conservation effort put forth by Rice's Facilities and Engineering (F&E) Department involves retrofitting all campus toilets with a low flow flush valve. This proposal is currently being tested in selected buildings (Valentine 4/1/98). In our analysis we calculated that implementing these valves, within the colleges alone, would save the university $18,696 per year.

 Water recycling systems offer more innovative conservation capabilities that allow unobtrusive water conservation. Along these lines, F&E has proposed a plan to recycle air conditioning condensate in three major buildings on Rice's campus. They estimate a return on this investment within three years along with considerable savings in subsequent years (Muiioz 3/30/98). Another recycling system that merits further investigation is the reuse of graywater for toilets or irrigation.

 Lastly, a concerted effort should be made to educate the Rice community about the quantity of water used and water conserving habits. This could be most easily and effectively achieved by combining efforts with other environmentally conscious campus groups.

References

Fagan, Daniel. "A Discussion of Water-Conserving Plumbing Fixtures." Heating/Piping/Air Conditioning April 1998: 43-47.

Lopez, Joe. Personal interview. 30 March 1998.

Muñoz, Jeff. Personal interview. 30 March 1998.

Muñoz, Jeff. Personal interview. 13 April 1998.

Valentine, Eric. Personal interview. 1 April 1998.

Valentine, Eric. Personal interview. 14 April 1998.