The Potential of Greywater Reuse in Residential Areas of Vancouver by rhee208


									The Potential of Greywater Reuse in Residential Areas
                    of Vancouver

                                               Vivian Rhee
                                               # 70157094
                                               ENGL 112
                                           Dr. Erika Paterson
                                           1st December 2009

Looking at residential, urban cities like Melbourne, Australia and Berlin, Germany, Vancouver has
substantial potential to adopt the concept of greywater reuse system in order to reduce the city’s water
consumption level, or water-abuse level, in the residential areas. This paper demonstrates the method of
initiating a greywater system in addition to examining the safety of greywater reuse in the two
aforementioned cities that have been using the water treatment system for many years. From the
observation of the positive outcomes of Melbourne and Berlin, the City of Vancouver and the Plumbing
Department should truly consider implementing the greywater reuse system for garden irrigation and
toilet flushing to promote water sustainability.
   1. Introduction

       Despite the seeming abundance of water on Earth, the amount and quality of fresh water
is diminishing. This is becoming further evident as more rural areas, such as Benxi City in China,
are industrialised and more toxic waste is produced and eliminated into fresh water (Cui and
Yang 1998). However, there are many cities that are very sufficient in water like Vancouver.
Vancouver is on the coast of the Pacific Ocean and contains numerous rivers and plentiful
rainfall that compose the city’s water source and hydroelectricity. Consequently, the
irresponsible use of water by the city’s population, especially in residential homes, leads to an
unsustainable way of life. Although lawn sprinkling regulations have been applied since 1993,
these regulations alone are not enough to promote water sustainability (Metro Vancouver).
Therefore, the implementation of the greywater reuse system in the residential areas may be a
solution to the persisting water-abuse problem. Greywater reuse is the recycling of water from
laundry, showers, and baths for water usage usually in garden irrigation and toilet flushing (Al-
Jayyousi 2003). The idea of greywater reuse is not new. Scholars, such as Christova-Boal et al.
(1995) and Nolde (2000), report on greywater reuse experiences that have been in use for many
years in the cities of Melbourne, Australia and Berlin, Germany respectively. To demonstrate the
safety of greywater reuse, Christova-Boal et al. (1995) and Nolde (2000) perform scientific
experiments on the two cities’ greywater systems. Vancouver, being similar to Melbourne and
Berlin by the fact that they are residential, urban cities, therefore, seems to have the potential to
adopt the concept of greywater reuse, thereby promoting water sustainability.

   2. Background

2.1 Water Consumption Level of Canada

       In 2008, the Conference Board of Canada [TCBC], an independent, non-profitable
research organisation, graded Canada’s water sustainability level with a letter grade “D” (TCBC,
2008). This assessment was due to the fact that Canada’s water consumption level is more than
twice the average of sixteen countries (U.S., Canada, U.K., Denmark, Austria, Japan, Italy,
Ireland, Switzerland, Finland, Sweden, Norway, Netherlands, Germany, France, and Australia)
that were being compared with Canada, ranking in fifteenth place. Water consumption per capita,
measured in million cubic metres, is calculated using national population data from the United

Nations Population Division. TCBC identifies that Canadian homes use over 300 litres of water
per person per day. While continuing to calculate the consumption level, or water-abuse level, in
this way, TCBC adds that Canada’s water consumption per capita is over nine times greater than
the U.K. If this reflects the water sustainability stage of Canada, then how does it compare to the
water sustainability level of just one city, particularly Vancouver?

2.2 Water Consumption Level and Sustainability Efforts of Vancouver

       Webster (2009), a sustainability design researcher, refers to Hallsworth, the writer of the
Water Foundation Paper, to points out from a table of Metro Vancouver’s water consumption
level by sector of Metro Vancouver in 2000 that the residential sector uses 56% of all the water,
which equates to 680,000,000 litres out of a total of 1,200,000,000 litres per day. This level of
water-abuse is alarming as it is more than twice that of the consumption levels of agriculture,
industry, and commercialism, which are the three main counteracting sectors of water
sustainability for Canada (TCBC 2008). In an attempt to promote water sustainability, in 1993
Metro Vancouver introduced the Water Response Plan, a plan of water restrictions in an effort to
reduce peak summer usage, which showed immediate results of a significant reduction in water-
abuse (Webster 2009). In addition, the replacement of the combined sewer system commenced in
1996 due to the overflow of storm water and untreated sewage into the river and ocean.
Furthermore, in 2001, Vancouver approved the Liquid Waste Management Plan, “a key strategy
and shift in thinking of stormwater as a resource, not a waste” (1).

   3. Methodology

       Scholarly articles suggest that there is an underlying series of requirements that need to
be met when implementing a greywater reuse system to a household or community. Firstly, the
greywater that is to be used should fulfil four criteria: hygienic safety, aesthetics, environmental
tolerance, and technical and economical feasibility (Al-Jayyousi 2003). Next, the country’s
guidelines and standards of water reuse in buildings should be reviewed. However, as it seems
that Canada does not acquire such specific guidelines, it would, thus, be best if the guidelines of
countries that have already been using the greywater reuse system were reviewed (e.g. U.S.,
Japan, Germany, and Australia). Al-Jayyousi claims that since more money is actually spent to
collect, treat, and transport the greywater when reused at distant places, it is more effective to use
it for smaller systems (i.e. a household, a neighbourhood, or a community). In addition, both Al-
Jayyousi (2003) and Nolde (2000) emphasise how biological treatment, the removal of
biodegradable material, is crucial and “indispensible” (Nolde 2000: 282) to greywater reuse.

   4. Safety of Greywater reuse

       The primary concern of the greywater researchers is the public health risks associated
with the fact that greywater contains pollutants, metals, and other elements. Therefore,
Christova-Boal et al. (1995) and Nolde (2000) assess the quality of greywater used in Melbourne
and Berlin respectively. In Berlin, Nolde (2000) indicates that since the conceptual introduction
in 1995, the greywater systems are still operating today with no public health risks. Citing Lücke
(1998), Nolde claims that using stormwater or greywater systems can be cost effective as the
treatment and distribution of service water should not demand more energy and chemicals than
that needed for conventional systems. After testing random samples of greywater from the
present greywater system, the results showed that the composition of greywater is dependent on
where the source is from, whether it is from washing machines or from showers and baths, and
that the measured bacterial concentration in treated water were usually significantly low. In
response to Nolde’s conclusion, Christova-Boal et al. (1995) determine the volume and the
substances of each source of greywater for garden or toilet applications. Results showed that
bathroom, shower, and hand basin water is better for garden irrigation; laundry water, which has
high levels of salt, is better for toilet flushing. Furthermore, after the examination for harmful
microorganisms (Salmonella spp., Campylobacter spp., Giardia and Cryptosporidia) Christova-
Boal et al. confirm that the greywater is safe to use for the aforementioned garden and toilet

       However, Nolde (2000) and Christova-Boal et al. (1995) also comment that there are
some problems with the greywater treatment systems in the means of design and operations, and
the occasionally inadequately treated greywater. In accordance with Christova-Boal et al. (1995)
the “[retrofitting]” of an existing house is difficult because of “insufficient hydraulic head and
the consequent need to use a pump; floor level outlets near to ground level, resulting in the
collection tanks being installed below ground level and the need for ground anchoring; and the
long collection, distribution and overflow of pipelines” (393). Expanding on the health risk

concern of inadequately treated greywater, Al-Jayyousi (2003) advises that the most successful
greywater treatment is achieved in its immediate processing and reuse before the anaerobic,
oxygenless stage is reached. In correspondence to these problems, the scholars suggest that the
greywater reuse system be incorporated to the initial design of a house if possible and that in the
case of a system blockage or malfunction, the greywater must be automatically transferred to a
sewer (Christova-Boal et al. 1995; Al-Jayyousi 2003).

   5. Conclusion

       In the concluding remarks of Al-Jayyousi (2003), the idea is put forth that greywater
should be seen in terms of its “contribution to sustainable water development and resource
conservation without compromising public health or environmental quality” (190). Comparing
the many, but similar, results of greywater quality inspection, it appears that greywater is safe to
use for garden irrigation and toilet flushing in residential homes. Therefore, in consideration of
the results found in the greywater quality test performed by Christova-Boal et al. (1995) and
Nolde (2000), it seems that the City of Vancouver and the Plumbing Department should not have
an excuse for the disapproval of the implementation of greywater reuse in residential households,
especially since it is more efficient and convenient to integrate the treatment systems into smaller
developments, such as a household, rather than a large city. For Vancouver, especially with its
abundance of water sources, the potential initiation of the greywater concept should not be
difficult if the guidelines of other countries’ greywater construction are followed. Since the
scholars mention that the reason for the initiation of the greywater reuse system in other
countries (Japan, US, and Australia), was not specifically to promote water sustainability, but to
address the issue of water scarcity as a “short-term reaction” (i.e. an immediate and almost
instinctive solution), Vancouver should, I want to suggest, initiate the concept to reduce the
water-abuse levels in the residential areas (Al-Jayyousi 2003: 187). As a result, further research
concerning the City of Vancouver and the Plumbing Department’s refusal of greywater reuse
should be required. Finally, from the many investigations that were consulted, greywater reuse
“[proves] to be technically feasible” (Nolde 2000: 283) as the treatment system helps to
“conserve and optimise” (Al-Jayyousi 2003: 183) the use of water resources.

Annotated Bibliography (CSE style)

Al-Jayyousi OR. Greywater reuse: towards sustainable water management. Desalination
        [Internet]. 2003 Jan 15 [cited 2009 Oct 29]; 156(1-3): 181-192. Available from: http://
Al-Jayyousi (2003) assesses "the role of greywater reuse in sustainable water management in
arid regions", specifically in Jordan. More importantly, Al-Jayyousi demonstrates the steps
needed to implement a greywater reuse system (fulfill the four criteria, look out for the country’s
guidelines and standards for water reuse in buildings, and types of treatments). Al-Jayyousi’s
method outlines Vancouver’s possible application of greywater reuse.

Christova-Boal D, Eden RE, McFarlane S. An investigation into greywater reuse for urban
        residential properties. Desalination [Internet]. 1995 Aug 12 [cited 2009 Oct 29]; 106(1-
        3): 391-397. Available from:
Christova-Boal et al. (1995) investigate the practicalities, costs, and social attitudes of greywater
reuse in homes in Melbourne, Australia by conducting social surveys and performing tests to
determine the potential health and environmental risks of greywater reuse. This article is
important because it focuses on the greywater reuse system in residential households and even
talks about the problems and solutions of “[retrofitting]” houses with greywater reuse systems.

Cui F, Yang X. Sustainable development of the seriously polluted cities in China. Chinese
       Geographical Science [Internet] 1997 Sep 29 [cited 2009 Nov 11]; 8(4): 343-351.
       Available from:
Cui and Yang (1997) discuss a method for a sustainable development of severely polluted cities
in China, particularly Benxi City. This article informs the reader of the pollution level in Benxi
City and how environmental protection policies should advance as the urban and economic
processes of a city develops.

Metro Vancouver (Canada). Lawn Sprinkling. Vancouver: [cited 2009 Nov 14]. Available from:
Metro Vancouver informs the readers of purpose and details of the lawn sprinkling regulations in
Vancouver. The article helps me to understand Vancouver’s efforts in trying to reduce water
consumption levels.

Nolde E. Greywater reuse systems for toilet flushing in multi-storey buildings- over ten years
        experience in Berlin. Urban Water [Internet]. 2000 Jul 26 [cited in 2009 Oct 29]; 1(4):
        275-284. Available from:
Nolde (2000) introduces the background of the first greywater reuse system in Berlin, Germany,
and like Al-Jayyousi (2003), Nolde addresses the greywater reuse guidelines and problems of the
reuse systems, and explaining the system concept and methodology. Furthermore, Nolde believes
that greywater reuse is reliable for toilet flushing and doing the laundry. This article is valuable
because it proves that greywater reuse system is a reliable way to conserve water as it has been
successful in Berlin for ten years.

[TCBC] The Conference Board of Canada. Water Consumption. Analysis. Ottawa: Brenda
         Lafleur; 2008 Oct [cited 2009 Nov 14]. Available from:
TCBC (2008) analyses the water consumption levels of sixteen countries including Canada.
TCBC criticises Canada of having one of the worst water consumption levels, ranking fifteenth
place. The article addresses the reasons behind the high water consumption level, which is useful
for this essay.

Webster S. Sustainability by Design Research Roundtable. [information booklet]. Vancouver,
       BC: University of British Columbia; 2009 Mar [cited 2009 Nov 14]; [6 p]. Available
Webster (2009) investigates water infrastructure and the impacts that climate change and
increased population will have on water in the Metro Vancouver region over the coming years by
analysing the water supply, distribution, treatment, and consumption of Metro Vancouver.
Webster also acknowledges me of a possible water sustaining method, which is stormwater
management. This is similar to the idea of Dixon et al., which is to combine greywater and
rainwater for reuse.


To top