Water Waste and Recycling
By Ayden Kim
Green Issues Research Paper Assignment
AR831 Environmental Science 1
Fall 2014
Water is most basic elements for human activity and it is under serious threat due to
excessive demand. Rapid growth of human population is pushing its fixed available supply to its
limits. Throughout the human development, we as human tried to manage the water usage in
many different ways, however, it is critical today to act productively to manage the water waste
more than ever before. “The volume of water in the world never changes, but only 2.5 percent is
fresh, and more than two thirds of this is unavailable for human race.” (Black and King, 20)
Let’s discus the cause and effects on current water issues. “By 2025 nearly 2 billion
people will be living in water short regions” (Black and King, 22) Global water shortage is not
mainly caused by reduction of total supply of water, it is more caused by the growth of
population and industry growth and their usages.
Source: International water management Institute
There are three types of regions about the shortage of water. First area is Physical water scarcity
areas where the water resource development is approaching or has exceeded sustainable limits
and more than 75 percent of river flow is extracted for agriculture. Second area is Economic
water scarcity areas where the limited access to water even through natural local supplies are
available to meet human demands and less than 25 percent of water extracted for human needs.
Third area is the little or no water scarcity area where the abundant water resources relative to
use, with less than 25 percent of water extracted for human purposes. Climate changes also
impact on our fresh water ecosystem, including melting ice sheets and alterations in rainfall
patterns. Climate change is expected to affect rainfall river flow and freshwater supplies in many
and complex ways, and the negative impacts will outweigh any likely benefits. The increase in
global temperatures is affecting the hydrological water cycle influencing the time and amount of
rain falls which will eventually increase the risk of floods. Also by increase in temperature, it
will speed up the melting of ice that change the amount that will flow from the mountain which
also can cause more floods. These effects will eventually worsen the quality of world’s fresh
water. “By 2080 up to 20 percent of people will live in areas with increased flood risk” (Black,
32) According to the research, 70 percent of water is used by agriculture, 20 percent is used by
industry and 10 percent is used by domestic. Urbanization is also causing the world water
shortage. “World became predominantly urban. With more inhabitants living in towns and
cities than in the countryside, huge pressures are exerted on municipal infrastructure and service
provision” (Black, 34) Due to rapid urban growth, although progress of providing the water
access, the pace of growth is so fast, it is hard to catch up the need of water. According to
Global Health Observatory (GHO) the urban population in 2014 accounted for 54 percent of the
total global population, up from 34 percent in 1960, and continues to grow. The urban
population growth, in absolute numbers, is concentrated in the less developed regions of the
world. It is estimated that by 2017, even in less developed countries, a majority of people will be
living in urban areas. “The global urban population is expected to grow approximately 1.84
percent per year between 2015 and 2020, 1.63 percent per year between 2020 and 2025, and 1.44
percent year between 2025 and 2030” (GHO)
Irrigation is another issue that causing the water shortage. “A fifth of the world’s
cropland cannot support agriculture purely on rainfall, so farmers use water from rivers, lakes, or
aquifers (“blue water”) to cultivate their crops” (Black, 62) The majority of irrigation water is
from aquifers and this source of water is also under a threat. The way to improve is to find the
better way to capturing and storing green water and improve the soil quality to that it can hold
the water much longer in the soil.
Lastly industry has big impact on water. Most every manufactured product uses water in some
point of production. “just over 20 percent of all fresh water withdrawn worldwide is used by
industry, although in high income countries this proportion rises to nearly 60 percent” (Black,64)
According to USGS “For 2005, withdrawals were an estimated 18,200 million gallons per day.
Industrial withdrawals were about 4 percent of nation’s total withdrawals and about 9 percent of
total withdrawals for all categories excluding thermoelectric power.
Source: USGS
As an architect, how can we design a building or land that reduce the water waste and
create recycling process that help to address the water shortage problem? What are the current
methods for reducing water waste for using water more efficiently? First of all, we have to
integrate the waste water treatment into our design concepts. Only high quality potable water is
need for drinking, washing, and cooking other water like rainwater and gray water can be
recycled for other usages like flushing the toilet, cooling and irrigation. This recycled water can
help reduce the demanding of high quality potable water while reducing the water waste.
There are four major ways to reducing the water waste. First, increase the use of rainwater
collection and gray water reuse system. Second, create and develop the space for ease of
collection, treatment, and reuse. Third, create a collection space within the building and
architecture system that the collected rainwater can distribute easily. For last, develop the use of
biological on site wastewater treatment such as wetland.
According to the Uniform plumbing code, gray water is “untreated household wastewater
which has not come into contact with toilet waste. Gray water includes used water from
bathtubs, showers, bathroom wash basins, and water from clothes washers and laundry tubs. It
shall not include wastewater from kitchen sinks or dishwashers” (USGBC, 2009, 436) One way
to use gray water is the GWHR Graywater heat recovery system, which recapture the heat from
the graywater and redistribute the heat to hot water system. The Graywater Heat Recovery
system is encourage to use in commercial buildings where the large quantity of hot water is
needed like apartment buildings and restaurants.
Source: Bob Gagnon Plumbing and Heating – Graywater heat recovery system
Collecting rainwater is also the popular way to conserve the water for other application.
Usually the rainwater is collected from the roof and directed to water storage system near the
buildings and redistributed for non-potable purposes like flushing and irrigation.
The Nidus Center for Scientific Enterprise in St. Louis has above ground storage tank to collect
rainwater from the roof and store for irrigation. (Mara, Leed Then and Now)
Other way to improve the water efficiency is Green Roof system. Green Roof system is
where roof is planted with vegetation to enhance the rainwater management. It has multiple
benefits such as reducing the rainwater runoff quantity and slower release and improvement in
water quality of storm-water runoff. It also help to maintain stable interior temperature and
humidity so that building can save the heat energy which also related to water usage.
For example, Commerzbank Headquarters in Frankfurt, Germany and Dutch Pavilion, Expo
2000 have a green roof system and interior gardens to conserve and reuse the water more
efficiently.
Commerzbank headquarter - Source: Gissen, Big and Green, 90
Dutch Pavilion, Expo 2000 – Source: Gissen, Big and Green, 94
Constructed wetlands and waste water treatment system are other way to conserve water.
Constructed wetland can be either surface or subsurface flows which surface flows resemble
marshes and subsurface flow support wide variety of plants.
Source: Yudelson Green building A to Z, 185
Understanding the relationship between greenery, water and waste is critical today for
architects to manage the water consumption and reduce the water waste. Today, due to the fast
growing of population and urbanization, we use millions of gallons of water everyday while
millions of gallons of rainwater can run off to sewers and into the ground. By constructing
above methods (wetland, Green Roof, collecting rainwater, and recycle graywater) can improve
the water waste and efficiency and architects and engineers should cooperate with each other to
create better solution for water waste and eventually create a way to transform wastewater to
drinking water.
Resources
1. Water and energy savings from on-demand and hot water recirculating system
Randi H. Brazeau and Marc A. Edwards
2. Water efficiency measures
Dennis F. lynch, M.Arch., AIA, LEED AP, and Deborah K. Dietsch, March., Hon. AIA
3. Sustainable Design for Interior Environments
Susan M. Winchip
4. Green Building A to Z – Understanding the Language of Green Building
Jerry Yudelson
5. Cities People Planet
Herbert Girardet
6. The Guidebook to Sustainable Design
Sandra Mendler, AIA, William Odell, AIA, Maryann Lazarus, AIA
7. Sustainable Landscape Construction – A Guide to Green Building Outdoors
J. William Thompson and Kim Sorvig
8. Sustainability in Interior Design
Sian Moxon
9. Big and Green - Toward Sustainable Architecture in the 21st Century
David Gissen
10. The Atlas of Water – Mapping the World’s Most Critical Resource
Maggie Black and Jannet King
11. Graywater systems help Recycle, Reduce Waste – City of San Diego Public Utilities Water and
wastewater
12. Residential Graywater Systems – the city of San Diego Development Services –July 2014
13. Energy Manual : Sustainable Architecture – Manfred Hegger, Matthias Fuchs- 2008
14. Guidelines for Water Reuse – U.S. Environmental Protection Agency – September 2012
15. Water Recycling and Reuse : Potential, Safety and Best Practices – International Water
Assoication
16. The Greening of Affordable Housing Through Public and Private Partnerships : Development of A
Model for Green Affordable Housing – Yong Han Ahn, Yuhong Wang and Myung HwJeon
17. Efficient heating and cooling systems for low-energy houses – Vasile Minea
18. Green Water Technologies and Resource Management for Water System Heat-Transfer
Applications in the Built Environment – Colin Frayne
19. A compact reactor system for processing grey water and its reutilization for flushing toilet
Bowls – Janez Brtovsek, Magda Cotman and Albin Pintar – Aug 2014
20. Characterizing microbial quality of household greywater
Joanne O’Toole, Martha Sinclair, Manori Malawaraarachchi – July 2014