Water savings in universities: the São Paulo campus method that cut 52%

Water savings in universities work as a permanent programme, not a campaign: diagnosis building by building, leak hunting in the pipe networks, fixture replacement, a review of laboratory uses and continuous metering. That is how the University of São Paulo’s Water Conservation Program, PURA-USP, cut the monthly water demand of its main campus by 52%, from 137,881 to 66,247 m³ a month, between 1998 and 2014. The method is published and works for any campus.

In short:

• In 1997, water was 16.79% of the university’s operating expenses, excluding staff and investment, twice the share of electricity. In 2003, it was 6.24%.
• The programme started with the 7 units that accounted for about half of campus consumption, with some 8,300 points of use reviewed.
• Laboratories are the extreme: the Institute of Chemistry cut consumption by 70% by 2001, and the campus’s 240 distillers lost about 50 litres of water for every litre distilled.
• Metering by building and remote meter reading turn night-time consumption into a leak alarm and make it possible to bill restaurants and other third parties for their water.
• Results last with permanent management: four years after the works ended, the first-phase units were still using 48% less.

Why does water weigh so much in a university’s budget?

Because a campus is a city with old buildings, many people and special uses. The University of São Paulo’s main campus, in São Paulo, when the programme began:

Item	University of São Paulo main campus
Built area	740,000 m², in some 250 buildings, most from the 1960s and 1970s
Population	58,546 people
Water connections	122
Consumption in 1997	150,000 m³ a month
Weight of water in operating expenses	16.79%, against 8.26% for electricity and 4.87% for telephones
Maintenance	Small teams and no preventive maintenance

Decades-old buildings, plumbing never modernised and laboratories with equipment that uses water all day explain the bill. In the United States, the EPA estimates that laboratories can use five times as much drinking water as other commercial buildings of the same size.

How do you set up a water conservation programme on campus?

By planning before intervening. The article by three members of PURA-USP, published in 2006 in the journal Ambiente Construído, describes the method in three stages: planning, implementation in five steps and permanent management.

Planning answers four questions: why (the weight of water in the budget), what for (how much to cut, and how fast), where (the state of the buildings and networks) and who. At the university, the answer to “who” was a central committee, which planned, specified the fixtures, hired the contractors and managed demand, and a committee in each unit, which bridged lecturers, management and maintenance.

Implementation was phased, starting with the units that used the most: 7 units with about half of campus consumption in 1998 and 1999, the other 21 in 2000 and 2001, and 9 units outside the main campus in 2002. In each unit, five steps:

Step	What is done	At the University of São Paulo
1. Diagnosis	Buildings, networks, points of use and consumption history of each unit	An intervention plan with the points of greatest potential
2. Physical losses	Leaks in external pipes and storage tanks, with listening sticks, electronic geophones and noise correlators	External pipes and, in the tanks, especially float valves and overflows
3. Points of use	Internal leaks and replacement with water-saving fixtures	About 8,300 points in the first phase and 10,900 in the second
4. Habits and activities	Kitchens, laboratories, irrigation, cleaning and air conditioning	A study of the distillers and of reusing their cooling water
5. Outreach and training	Campaigns, manuals and training for maintenance staff and users	A survey of 450 first-phase users

The replacements followed guidelines by type of room: self-closing taps with aerators in washrooms, presence sensors in auditorium washrooms, 6-litre toilets instead of those of 9 litres or more, self-closing valves on changing-room showers, lever taps with aerators in kitchens and pantries, and aerators or flow restrictors on laboratory taps, where possible.

How do you cut water use in university laboratories?

Starting with the distillers. The University of São Paulo campus had 240, most of the same type, and they lost about 50 litres of cooling water for every litre of distilled water. The solutions range from the simplest to the most sophisticated:

• Adjust the water inlet of the distiller, which often runs above what is needed.
• Recirculate the cooling water, as some users were already doing.
• Switch to more efficient purification systems, such as reverse osmosis or ultrapurification, according to the water quality each research project requires.

The same reasoning applies, the authors say, to other laboratory processes that use water. The programme’s rule was to find the best local solution without compromising research, always together with the people who use the equipment. Laboratories, which use more water and hide leaks more easily, were also where the programme achieved the largest reductions.

How do you meter each university building’s consumption?

With sub-metering and remote meter reading. The University of São Paulo programme calls what comes after the works demand management: organising the data, setting control parameters (monthly consumption, consumption per person, flow profile) and acting when something drifts. The steps:

1. Register the connections. Check each connection, what it supplies and the state of the meter box and meter, and reconcile the register with finance and the water utility. The university had 122 billing connections.
2. Meters per building. By 2003, the university already had 55 of the 235 planned sub-meters.
3. Remote meter reading. Automatic reading shows the daily profile and the minimum night-time flows, which reveal leaks before the bill does.
4. Quotas per unit. With consumption metered, each unit can have a quota, allowing for seasonality, and answer for whatever exceeds it.
5. Billing third parties. Restaurants, snack bars and other concession holders on campus pay for the water they use.

Campus consumption varies with holidays, conferences, timetable changes, renovations, filling swimming pools and new laboratory equipment. That is why the programme compares period with period and looks for the cause of each variation, instead of looking only at before and after. How remote reading finds leaks through the consumption pattern is explained in remote water consumption monitoring.

How much can a university save?

The University of São Paulo’s first-phase results, unit by unit, show how the type of use changes the response:

Unit	Type of use	Reduction by 2001	Reduction by 2003
Institute of Chemistry	Laboratory	70%	56%
School of Pharmaceutical Sciences	Laboratory	69%	60%
Institute of Biomedical Sciences	Laboratory	43%	35%
Polytechnic School	Mixed	39%	43%
University Hospital	Hospital	35%	48%
School of Economics, Business and Accounting	Human use	24%	39%
School of Philosophy, Letters and Human Sciences	Human use	20%	33%
First phase total		47%	48%

The authors explain the swings between 2001 and 2003: a major leak at the Institute of Chemistry, building works at the Institute of Biomedical Sciences and the repair of a problem in the University Hospital’s storage tanks. Across the whole campus, the reduction reached 36% in 2003 and 52% in 2014. And the weight of water in operating expenses fell from 16.79% to 6.24%, even with the water tariff 69% higher between 1997 and 2003.

How do you keep the savings after the works?

By making the programme permanent. The authors’ conclusion is direct: water conservation takes much more than fixing leaks and replacing fixtures. It takes a permanent programme, continuous demand management and, above all, a change in users’ behaviour.

The survey of 450 first-phase users showed the ground: 98% said they saved water and 76% told a staff member when they saw a leak. The most cited complaint about self-closing taps was the difference in closing time from one tap to another, which maintenance itself can adjust. Listening to users, reporting results back to them and replacing reactive maintenance with preventive maintenance are part of the method.

For schools and secondary education, with a ready-made project to run with students, see water savings in schools.

How does T&D help universities and colleges?

Through three paths, depending on the size of the in-house team. In SEA 360º, T&D handles implementation, with no construction work, with a baseline under the IPMVP protocol, efficiency technology at points of use, electronic leak detection, repairs and maintenance training, and continues with ongoing management and monthly reports on financial, operational and ESG performance. The ceiling observed in the full programme is a 70% reduction.

TDRR remote monitoring provides remote reading of reservoirs, pumps and hourly consumption, with alerts by app, text message or WhatsApp. And for institutions that want to run their own programme, HydroDesk combines technology bought by the university, team training and remote consulting, in a four-phase journey that reaches the sustainability report.

Frequently asked questions

How much water does a university use?

It depends on size and uses. On the University of São Paulo main campus, in 1997, it was 150,000 m³ a month for about 58,000 people, with laboratories, a hospital and restaurants. After the water conservation programme, demand fell to 66,247 m³ a month in 2014.

Where do you start saving water on campus?

With the units that use the most. The University of São Paulo started with 7 units that accounted for about half of campus consumption, also chosen to cover different types of use: laboratory, hospital, human and mixed.

Do laboratories use more water than classrooms?

They do. According to the EPA, laboratories can use five times as much drinking water as other commercial buildings of the same size. At the University of São Paulo, distillers lost about 50 litres of water for every litre distilled, and the laboratory units were the ones that cut the most.

What should a campus do about restaurants and snack bars?

Meter and bill them. With their own meter, each restaurant or snack bar pays for the water it uses and gains a reason to save. The kitchen measures are in water savings in restaurants.

Do a university’s water savings last?

They last when the programme is permanent. At the University of São Paulo, the first-phase units, whose works ended in 1999, were still using 48% less in 2003, and the campus reached a 52% reduction in 2014. Without continuous management, leaks and old habits come back.

Sources

• University of São Paulo, PUERHE: history of the Water Conservation Program, in Portuguese: a 52% cut in the main campus’s monthly water demand, from 137,881 to 66,247 m³ a month, from 1998 to 2014
• Silva, G. S.; Tamaki, H. O.; Gonçalves, O. M. Implementation of water conservation programs in university campi. Ambiente Construído, v. 6, n. 1, 2006, in Portuguese: planning, steps, fixture guidelines, distillers, demand management, user survey and results by unit
• EPA WaterSense, Types of Facilities: water use in laboratories
• T&D SEA 360º, TDRR and HydroDesk