Desalination & Reuse Handbook - Flipbook - Page 63
REUSE MARKET PROFILE
Potable reuse – either direct or indirect – remains a small section of the market, but provides a vital augmentation to water supplies for
an increasing number of people. Namibia’s Goreangab Water Reclamation Plant has piped treated wastewater directly into Windhoek’s
drinking water supply since 1956, with only temporary or small-scale parallels beyond the desert state. In the absence of federal
legislation governing potable reuse in the USA, state-level legislation in California, Texas, Florida and Arizona is beginning to create
more certainty that has enabled early-stage procurement for new projects to go ahead.
Groundwater recharge has seen greater uptake – the first 38,365 m3/d phase of Western Australia’s Beenyup Groundwater
Replenishment Programme came online in 2016, with a second currently under construction. Meanwhile in California, further
expansions are planned at the 378,500 m3/d Orange County Groundwater Replenishment System that will add 113,500 m3/d to its
capacity, and the Southern California Metropolitan Water District has tabled plans for its own 568,000 m3/d groundwater recharge
facility.
Treatment technologies
GWI wastewater reuse market data divides reuse technologies into three broad categories. Triple barrier treatment involves a
combination of micro- or ultrafiltration (MF/UF) with reverse osmosis (RO) and disinfection to produce high quality water, most
commonly for use as potable or process water. Tertiary reuse encompasses treatment technologies such as sand or media filtration
and disinfection, which are placed after secondary treatment trains. It also includes membrane bioreactor (MBR) technology, which
combines both secondary and tertiary treatment. A treatment train using MBR and RO treatment would be classified as triple barrier,
although this configuration of technologies remains relatively rare. Tertiary technologies encompass the largest segment of the reuse
market. ‘Other’ technologies encompass primary and secondary wastewater treatment and produce lower quality water, usually for
irrigation.
Tertiary and advanced wastewater treatment technologies make up an increasing proportion of globally contracted reuse capacity. This
has been driven by industrial demand for high quality water, and by upgrades to facilities that had previously supplied primary- or
secondary-treated water for irrigation purposes. As industrial demand increases and as more and more attention is paid to the quality of
water used in agriculture, in particular the presence of pathogens, the trend towards tertiary and advanced treatment capacity is expected
to further intensify. Compared to tertiary and ‘other’ treatment technologies, triple barrier reuse projects tend to be smaller in scale, but
represent far higher levels of capital investment per m3/d of new capacity due to the more advanced technologies involved. China and the
USA are the largest markets for these technologies in wastewater reuse, followed by Australia and India. Regulations on water reuse in
the US and Australia for agricultural or landscape irrigation applications are a key driver of triple barrier technology in these countries.
In China and India the majority of triple-barrier reuse has been for industrial customers, but tightening discharge regulations in China
have led to several recent awards using advanced treatment for environmental enhancement purposes.
In China and the USA, tertiary and ‘other’ treatment technologies stand in the region of 35–45% of total contracted capacity since 2010,
with triple barrier reuse accounting for 10–15%. This is largely reflective of industrial demand for higher quality water in China, and
regulations on pathogen contents for agricultural or landscape irrigation in the USA.
Contracted capacity by country and technology level, 2010–2017
30
Triple barrier
Capacity (million m3/d)
25
Tertiary
20
Other
15
10
5
0
China
U.S.
Mexico
India
Egypt Australia Spain
UAE
Saudi
Arabia
Israel
Source: GWI DesalData / IDA
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