Los Angeles, Water, and Harvey Mudd College An Evaluation of Water Use at Harvey Mudd College



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4.1Total Water Usage


Total water usage for Harvey MUDD was readily available through Tom Shaffer in Facilities and Maintenance (F&M). We were able to obtain aggregate billing data by meter for the campus back through 1993. A plot of the total water usage for the campus can be seen in Figure 4 .5. As can be seen from this graph, total campus water usage has been around 60,000 CCF for the past several years. This is equivalent to about 45 million gallons of water. Conversations with F&M have indicated that the small peak in 2003 can likely be attributed to the construction of Sontag Dorm, and that the rise last year may be due to the start of operations at the new dining hall. Tom Shaffer indicated that the new dining hall (Hoch-Shanahan Dining Commons) uses significantly more water than Platt Campus Center did when it functioned as the dining hall.

Ideally, this total usage will be broken down into end uses. The billing data we obtained from F&M was broken down giving us the water used on each meter on campus. This provided us with a starting place in trying to separate out the various end uses of water. Unfortunately, the meter numbers listed on the billing data did not correspond to the meter numbers listed on the CAD drawing of the water lines on file with F&M, the meter numbers also changed on the billing data in the mid 1990’s. We were also informed at this time of a couple of other schematic errors in the CAD drawing regarding the placement of lines to some of the buildings. Tom Shaffer toured the campus with us, and helped us to identify the locations and meter numbers of the meters on campus. We then updated the CAD drawing so that the schematic is correct and the meter numbers match the currently billed numbers. The updated CAD drawing can be seen in Figure 4 .6.



Figure 4.5: Historical plot of total campus-wide water usage from 1993 through present, as determined from billing data.


Figure 4.6: The updated schematic of water lines and meters for the HMC campus.


Figure 4.7: An overlay of meter locations and buildings served on a satellite photo of HMC's Campus.

In Figure 4 .7, you can clearly see the meter locations and which buildings they serve. The placement of the meters on HMC’s campus is central to determining water usage. The ideal scenario for determining end usage of water would be a meter on each building. This however, is not the case as the meters were installed exclusively for billing purposes. Notice first the meter on the line that spurs off west of N. Mills (N. Mills line). This line, and therefore the meter placed on it, accounts for the water usage of 11 buildings: Thomas Garrett, Kingston, Platt, Hoch-Shanahan, West Dorm, East Dorm, South Dorm, North Dorm, the LAC, Sontag Dorm, and Linde Dorm. This line also serves a large part of the irrigation for the section of campus west of N. Mills Ave and east of the sundial. Needless to say, this does not lend itself well to the separation of water into its end uses. In fact, the only dormitory that is on a meter in relative solitude is Atwood. There is some landscaping on that meter as well, but it is limited to the concrete planters around the dorm itself as can be seen in Figure 4 .8.

Figure 4.8: Sketch of landscaping on the Atwood Dorm meter


The large peak that is exhibited in Figure 4 .5 in 1995 has been attributed to a leak in the North Mills Line after conversations with F&M. A plot of the historical data for the North Mills line can be seen in Figure 4 .9. This data shows a peak in 1995 that is correlated with the peak in the total campus usage. In Claremont, leaks in water lines are particularly problematic because of our soil conditions. The natural soil in this area is very sandy. This means that leaks in lines are much more likely to percolate downward than if we had clay soil (in which case they would be much more likely to bubble up). This downward flow of the leaking water makes identifying the leaks difficult.

Figure 4.9: Historical data for N. Mills Line. Note the peak that corresponds with the peak in total campus usage.


4.2Campus Breakdowns


As mentioned previously, the four end use categories that we want to be able to differentiate are academics, dining, dorms, and landscaping. The most natural way for us to arrive at these breakdowns is to estimate the first three and assume that the remaining use goes to landscaping. We decided to do it this way because although we suspect that flow data exists for much of the campus irrigation system, we were unable to obtain it.

4.2.1Landscaping


The somewhat limited landscaping data we do have suggest that a percentage of total water usage well over 50% is not unreasonable. However, despite the large percentage that goes to landscaping, our irrigation system and landscaping is really quite reasonable for this region.

Often, the first things people notice about water usage at Harvey Mudd are the sprinklers on the grass up and down the middle of campus. These sprinklers are among the few of their kind left on campus, and while they are not always perfectly aligned, they are pretty close. Often overlooked are the large areas that have been transitioned to drip lines and native plantings since the recommendations of the 2000-2001 academic year clinic project [xxii]. The clinic project looked at evapotranspiration in plants to determine how much water they actually need as a function of weather. The clinic team’s test garden across from Atwood Dorm has served as a model for much of the landscaping renovation on campus. Also, in response to the clinic project’s results, Harvey Mudd installed a Rainbird Weather Station (Model number WS-PRO-PH) which tracks temperature, humidity, precipitation, and wind and controls the sprinklers across campus accordingly. The whole system is maintained and operated by Mike Barber of F&M.

Mike Barber is also responsible for the landscaping on campus. Many of the changes are being made according to a master plan drawn up by Bob Parry in 2001. A list of the native plants that Mike has been using across campus can be found in Appendix A. Star jasmine is being used to replace the very thirsty ivy in many areas. The undergrowth that used to surround the oak trees in many locations on campus has been removed, both because it was heavy water use, but also because these particular trees are much healthier without the growth around their roots. Many of the pine trees around the inner dorms are scheduled to be removed as well. This is not necessarily because pine trees in general need a lot of water, but because of the threat of the bark beetle. While conifers are typically fairly low water plants, keeping them wet enough to keep them safe from the bark beetle uses quite a bit of water. With regard to the large patches of grass that so often get cited as a water faux pas, they are here to stay. The lawn stays as it serves many purposes to the college. A day does not go by that there aren’t students playing Frisbee, or throwing a ball around on them. Classes get held out on the grass and students study and picnic on the grass. Furthermore, if that grass were to be removed, campus would be a lot warmer in the summer and much more unpleasant to walk down or be around. In terms of the landscape master plan, the ‘green belt,’ as its called, down the center of campus, as well as dorm courtyards and a couple other areas are marked as sacred areas that will not be modified to California native landscaping. Other locations of grass, such as the large swath in front of Olin, are also slated to remain unchanged in the plan as they serve as a public face for the college.

While we were not able to acquire solid numbers for irrigation usage, it is thought that the general trend of decline in the total water usage (Figure 4 .5) since 2001 has been due primarily to the installation of the new irrigation system and landscaping. If you further consider that the Eckert, Sparks, Chen lab (which will be discussed in further detail in the next section) came online about that time period, the probable water savings due to the landscaping changes are quite significant.


4.2.2Academic Use


Academic usage consists primarily of lab use, restrooms, and cooling tower usage. Luckily we know the usage for the majority of academics through three meters: Olin, Parsons, and Jacobs (see Figure 4 .6). The only problem is that each meter also has landscaping coming off of it. The cooling towers that serve Parsons, Olin, Jacobs and the Libra Complex pull water off of the Jacobs meter, so the Olin and Parsons meter are free of cooling tower water. However, both the Olin meter and the Parsons meter account for a large amount of irrigation area: the Dartmouth frontage area, and everything between Galileo and the sundial respectively. So we can only use numbers from these meters to make sure that our estimates are reasonable in order of magnitude.

Table 4 -1 shows our estimates for restroom use, which is based on an estimates enrollment of 720 students 65% of which are male and a known faculty/staff population of 280 (we assume 50/50 gender split). We take into account the estimated frequency with which men use flush-less urinals as well as the estimated frequency of bathroom use.



The other major use of water in academic buildings is use in labs. We are aware of the Eckert, Sparks, Chen lab that accounts for a very large portion of total campus usage. Table 4 -2 shows this lab usage and estimated common lab usage. Beyond the Eckert, Sparks, Chen lab, we estimate that the primary water use occurs in chemistry and biology labs. For a given section of a chemistry teaching lab, we made the assumption of a faucet flow rate of 2.5 Gal/min for an average sink (as an overestimate from a dorm survey) as well as about 3 minutes of flow per lab group with an average of 10 lab groups. With 14 week labs and a lab section every weekday, the yearly usage in labs from anything like washing hands is so small that we can neglect it in our calculation. We also noted that dishwashing for beakers and such also does not contribute significantly (Hand washing 40 min/wk for 6 labs: ~35 CCF/year). So we will say that labs account for less than 100 CCF a year. Since we saw that toilets account for around 1037 CCF the academic total is around 6760 CCF yearly plus cooling towers. We have no real way to estimate the usage at the cooling towers, so we assume that they use twice the restroom usage. So the current usage at academics is around 8800 CCF/year which is approximately 15% of total campus usage. However, the Eckert, Sparks, Chen Lab is replacing their current water needs with a closed system which should finish installation imminently. This will reduce the total campus usage by around 10%!

Table 4 1 Estimates for Academic Restroom Use







Est. Flush Volume

Weekly Avg.

Pop.

Total (30/50 wks)

Students

Toilet

4 Gallons

2 / person

720

231 CCF

Students

Flush Urinal

2 Gallons

1 / person

480

38 CCF

Students

Flush-less Urinal

0

2 / person

480

0

Staff

Toilet

4 Gallons

10 / person

280

749 CCF

Staff

Flush Urinal

2 Gallons

1 / person

140

19 CCF

Staff

Flush-less Urinal

0

5 / person

140

0




All

-

-

1000

1037 CCF

This table shows our estimates for the contribution of restroom usage in academic buildings. We use 30 weeks for the student population and 50 weeks for the faculty and staff populations. Note: 1 CCF = 748 Gallons.

Table 4 2 Estimates for Academic Lab Use






Constant Use

# Lab Sections

Use / Lab

Total

Eckert, Sparks, Chen

8 Gal/min[xxiii]

NA

NA

5621 CCF/yr

Generic Lab

0

5 / week

45 Gal.

~8 CCF/yr

Considering that the water use in the Eckert, Sparks, Chen lab will be eliminated from the campus usage imminently, we have plotted total campus water usage since 2001 (when the equipment came online) sans the water used by the lab (Figure 4 .10). This serves to illustrate the lower water usage that should start corresponding to HMC’s total water use in summer 2007.



Figure 4.10: The red line is the total water use since 2001 with the Eckert, Sparks, Chen lab water removed. The blue line is the total water used by the campus for reference. It should be noted that the use by the Eckert, Sparks, Chen lab is of the same order as the peak due to the construction of Sontag dorm.



4.2.3Dining Hall Use

The dining hall usage should be primarily from dishwashing and cooking. We expect that the water used for cooking is probably dwarfed by the dishwasher use, so Table 4 -3 shows our estimates for yearly use at Hoch-Shanahan. We estimate that Hoch-Shanahan uses under 3% of the total campus usage including water used for cooking.

Table 4 3 Estimates of Dining Hall Usage

Gal/hour

Hours of Use

School Year

Summer

Total

300xxiv

7am-9pmxxv

30 weeks

6 weeks

1415 CCF/yr



4.2.4Residential Use


Dorm water usage is a potentially highly variable amount depending on the building based on the plumbing. For example East (Marks) was built in the 1960s and Sontag is LEED Certified and was built in 2003. Since there is not much separation in the metering data for the dorms, we were forced to use the Atwood meter, which you will recall was relatively isolated on its meter, to predict student usage. We couldn’t use the Case meter as it includes a large portion of landscaping and the cooling tower that serves Case and Linde. The assumption here is that the landscape usage off the Atwood line is minimal. We feel that this is an acceptable assumption because the usage by Atwood was actually higher in the years that the landscaping north of it was not in place due to construction. Also, it currently only provides water to a small number of concrete planters as can be seen in Figure 4 .8.

Given that Atwood has on average 132 residents, in 2005-06 they used 2268 CCF for the 36 weeks of occupancy, which is 17.2 CCF per person. Realizing that there are plumbing differences and that this includes some landscaping, we assume 700 students which means that dorm usage is around 12000 CCF or 20.7% of total campus usage. What is interesting about this result is that students have the opportunity to seriously impact HMC’s total usage with conservation efforts! To this end we have created a dormitory water survey that is currently being conducted. See Appendix B for a copy of the survey. The survey is designed to be distributed with one of our water audit kits. A water audit kit consists of a stopwatch as well as a large graduated bucket and a smaller graduated container for measuring shower and faucet flow rates respectively. We also include a pressure gauge and adapter to a faucet so that students can check the static pressure in their pipes. While this does not tell us much about the water usage, it is an important check on the health and status of the plumbing in the buildings. Indoor plumbing should have a static pressure of around 50-60 psi. Too low of a pressure results in an unpleasant use experience, but too high of a pressure can cause damage to the pipes over time especially at corners and junctions in the pipes. A pair of pliers is included with the kit to make sure that students don’t hurt their hands removing the pressure gauge from the faucet. Finally, we ask students to report their toilet rating if it is printed on the unit and to report any leaks or other problems they have in their bathrooms. We also prepared a form that to be posted near a shower that asks students to record the date, time, and duration of their showers (See Appendix C). Our hope was to determine a reasonable average for student shower time. Since we think that is will account for the majority of residential usage, combining this number with the flow rates we obtain from the audit should allow us to make better estimates of residential water usage.

Figure 4 .11 shows preliminary results that we have gotten so far from the use of these kits. Two campus groups, Engineers for a Sustainable World (ESW) and Mudders Organizing for Sustainable Solutions (MOSS) were very helpful in gathering the data.

Figure 4.11: Preliminary results from water audit kits. Not every dorm is represented and only a few points have been collected from each dorm.


As expected the older dorms have higher flow rate showers and no reported ratings on the toilets. This data is preliminary since very few data points have thus far been collected for each of the dorms, and not all dorms are represented yet. Sontag, which is a LEED certified dorm, has low-flow toilets as well as reasonably low flow rates from both faucets and showers. Atwood, another of the newer dorms also has low-flow toilets and fairly low flow rates for showers and faucets.

4.2.5Landscaping Use Revisited


Now that we have estimates for dining, residential, and academic uses, how much is left to go to landscaping? Based on the previous arguments roughly 65% of our total water usage is going towards keeping the campus green. This agrees with our expectation of over 50%, but still leaves room for conservation in other areas to be effective.

4.2.6Final Estimated Breakdown

The final breakdown of current campus usage as we have estimated above can be seen in Figure 4 .12. We have also shown what the campus breakdown should look like after the Eckert, Sparks, Chen lab usage disappears.





Figure 4.12 Left: Current total campus breakdown. Right: Total campus breakdown sans Eckert, Sparks, Chen lab
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