Monday, June 15, 2020

Making More Water 2 -Water reclamation and reuse




Disaster in the making?

Conflicts over water use are already happening and Australia has already had a taste of what the  future holds. Recently  Adani 's Carmichael coalmine - the largest in Australia, was granted a licence to take 12.5 billion litres of water from the the Suttor River in the Burdekin Basin by the Queensland government, despite already being granted unlimited access to ground water from Australia's Great Artesian Basin for 60 years,  over the objections of farmers and farming communities in our arid interior,who rely on the Artesian Basin as their primary and most reliable source of water. As yet no comprehensive studies on the extent of the Basin have been done, though wells already have to be drilled deeper and deeper.
At the same time, in NSW, on the already very stressed Murray -Darling Basin, a massive 270 km long pipeline is being built to transfer water from it to the town of  Broken Hill. Half this water will also be allocated to mining, while towns and farms along the river itself are deprived of water and farmers are being forced off the land because they cannot compete with large corporations in a commodified water market, where the right to water is not determined by need or the desirability of the end product, but by how much you can pay.  

Since both the Murray –Darling and the Artesian Basin span several states and serve half the country, these scenarios highlight the need for water to be a national responsibility which should not be left up to individual states. We should not only be monitoring quality and quantity far more closely, but also sequestering water for human use and looking at future demand, before offering it to the highest bidder. 

Nor are we the only country facing such dilemmas. China is building 500 km pipelines to divert water from the Yellow River in the south to service Beijing in the country’s arid north, and in Chile the world’s largest mine, BHP’s Escondida is building two pipelines to transfer water from its coastal mines uphill to the Atacama desert - the driest place in the world and 3200m above sea level, because it can no longer take water from the artesian basin beneath it after clashes with other users during severe drought in 2016. Tensions are also apparent between countries over water rights, for example between Turkey, Syria and Iraq over the Tigris- Euphrates basin, between Israel, Jordan, Lebanon and Palestine over the Jordan River and between Egypt and other countries along the Nile. As populations grow and the world grows warmer, how can we meet our future needs without further conflict?

Could reusing waste water be the answer?

Thanks to the miracle of reverse osmosis, mentioned  in connection with desalination, many countries and at least 35 cities are now using recycled water to supplement their supplies.  Israel leads the charge by recycling 90% of its waste water, though other countries such as the USA, Mexico and China lead by volume. While Israel reserves its scarce fresh water supplies for drinking and uses its recycled water primarily for agriculture and to recharge aquifers to prevent salt water intrusion, Singapore, which recycles 55% via its New Water program (see below), uses it primarily for industrial and cooling purposes, although it is clean enough for domestic use, thanks to rigorous treatment and testing.


The tyranny of distance

Given that Australia's  black coal industry alone - mining and power generation, uses as much water as the entire city of Sydney with a population of five million, it would certainly be excellent to be able to use recycled water for high demand activities such as mining, crops such as cotton and timber, fire –fighting and the like,  and to leave our drinking water for human consumption as Israel does, but the high cost of dual systems or trucking or piping it from urban areas where it is generated to where it is needed, makes it prohibitively expensive unless we’re talking about compact countries such as Singapore,  Belgium or South Korea. Unfortunately most of the water used in mining is consumed and cannot be recycled.

On the other hand, you do have to wonder about the economics of building a 270 km pipeline at a cost of $500 million to Broken Hill on the one hand, while Sydney alone spent around $6 billion in the 1980s to pipe its waste water (around 1000 Olympic swimming pools worth a day) into the sea.

Fortunately, things have moved on since then. Sydney Water's  latest report says that it is harvesting storm water and recycling waste water to a small extent for firefighting, parks and gardens, cooling towers in commercial buildings as well as some industrial purposes. Though still a small part of its operations it has found that recycling is cost effective. It also has plans for drought response as well as integrated water management and land use planning. The latter includes cooling strategies and an organic waste strategy. According to the proposal, this should not cost more than "business as usual."[Let's hope that it isn't all derailed by the current mining activity beneath one of its main reservoirs, which is now being debated in the NSW parliament].


 

A brief look at Sydney's storm water management strategy which not only provides water which can be recycled either for industry or environmental benefits, but also reduces flood risks

There is no excuse in urban areas for industry not to make greater use of this water, especially if it is  available at a lower price as in Sydney. Sydney already sells 100% of its recovered bio -solids for agricultural purposes, to offset the cost of water treatment. It is also possible to recover minerals such as phosphorus and nitrogen. Where councils do not have the customer base to recycle on a large scale, individual industries may want to do it for themselves. We have already seen some of the closed loop systems employed by the textile industry which not only create enormous cost savings but prevent a great deal of pollution. India is rapidly becoming a leader in this field. Other examples come from the very thirsty paper making industry (see an Indian example below) and surprisingly, the brewing industry, which also uses copious quantities of water. Click here for an example in the fish processing industry in Ecuador, which seeks to minimise the cost of importing expensive fresh water.

Even when beyond the means of a single company,  several  could band together in an  eco - industrial park to take advantage of the various flows or to jointly fund treatment, especially if the industries themselves ensure that they have environmentally friendly inputs. Newer uses include cooling for large data centres such Google's in Belgium or Georgia (USA).





Other potential gains from treatment and reuse include power generation, heating and cooling – see for example Canada’s 2010 Winter Olympic Village which uses waste water for heating and hot water and achieves Carbon Neutral status.

Recycling might work in big cities  but what about the country towns which are running out of water but don't have a large customer base ?
In rural areas, smaller decentralised recycling plants, such as those made by the Fluence Corporation could ensure a constant reliable water supply, whether in drought or not. Although we have had rain in most parts of Australia, it will take several years before reservoirs reach their full capacity. What if recycled water from Broken Hill or other towns along the river, was sent to the mines instead of the mine depriving them of their drinking water? As yet, only two facilities in Australia treat water to drinking water standard and one of those is in mothballs for the present. However, even secondary or tertiary treatment may reduce pressure on water supplies and allow organic matter to be returned to the soil rather than the river. Minimally treated water could be used in cooling towers for coal fired power stations for example, while higher levels could allow recharge into groundwater or for environmental purposes such as maintaining river flows. However, even with the rigorous standards applied in Singapore, it would still require much more public education and trust in local authorities before Australians accept recycled water for domestic use and why should they be forced to pay more fore treatment because their drinking water has been allocated to other users?

Designing for the future

While dual piping is costly in existing facilities, there is no reason not to be planning for it in new buildings and subdivisions. South Korea is a leader in this field.  Listen to Tony Wong talking about better urban design for the future.Why not incorporate stormwater capture for landscaping and urban lawns? Nor would I have any objection to using used wash water - from showers or the laundry, for flushing toilets. In fact, speaking of flushing toilets, as cities grow and water scarcity becomes more common, shouldn’t we be designing toilets which don’t use as much water? The water closet has served us well for a century and a half, but what about a vacuum system, such as we have on planes, or using run – off from roofs for this?  We are after all, not using horses and buggies any more either, though they were popular at the time.


Sorry folks, this post is way too long, but I have had a bee in my bonnet about this topic for a while now and with the UN Day to Combating Drought and Desertification coming up on the 17th. it's surely  a good time to mention it.   

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