Week 11 - Retackeling Unwanted - Turning Contamination into Clean Water

As an extended thinking from the last entry, let's talk about clean water solutions.

In Los Angeles, it is well known that after a good amount of raining, surfers would stay out of water regardless the good waves. If they had enough bravery to be in the water for a while, they would probably be suffered from pinkeyes, a fever or diarrhea, as the water would be seriously polluted from stormwater runoff. There will be weird and funky smell and different kinds of rubbish and oils in the water. The severe stormwater pollution is affecting drinkable water as well.

Although our planet is mostly covered by water (roughly 70%), our drinkable water becomes scarcity in urbanisation progress. Poor stormwater management raises issue on contamination of drinking water. It has become an important action to prevent stormwater runoff located anywhere near drinking water sources.

Los Angeles launched a new solution in sourcing drinking water. It is called Stormwater Capture Master Plan. The project aims to keep rainwater runoff away from clean water, at the same time, turning polluted/stormwater, as a significant resource, into drinkable water.

Diagram of  Stormwater Capture Mater Plan in Los Angeles.

Integrated treatment on stormwater and water supply including a few design strategies. The first step is to capture and filter stormwater onsite from impervious areas. This includes some small rain gardens to create complex bioretention. Then, the simplest output is onsite direct use of filtered stormwater for irrigation. This is the smallest scale treatment in the plan. Larger scale including collect stormwater in urban area and redirect to underground infiltration galleries and bio-infiltration basins for treatment and then reuse for irrigation. Although there is still no further actions on treating stormwater into potable water yet, the principle inside the plan is making it wait-worthy.

In fact, stormwater collection and reuse for irrigation is spreading out and pretty common in Australia nowadays. What is uncommon is the thought on treating grey/black water into potable water.

Stormwater pit in normal residential gardens in Australia. (Photo source by author)

Actually, similar idea has been pioneered before Los Angeles. The idea was inspired by the turning sewage into potable water technologies in Wichita Falls, Texas. Wastewater treatment including putting additional chemical and biological processes before mixing the recycled water into regular potable water treatment. In 2013, Wichita Falls has spent $14 million on plant to start turning wastewater into drinking water and started to distribute to daily use. It was rather successful.

This is an incredible step in urbanisation era. Treating polluted water, at the same time resolving the issue on water shortage. The biggest concern today is the financial barriers. By introducing the new treatment, new technologies are necessary. Investments on new technologies would be huge. As well as, to make it prolonging, extra payment on daily water bills might be necessary. Would the citizens be willing to pay for the extra? How to resolve the financial issue? These are the issues left out behind the beautiful vision in the plan. It would be great if the technologies and the extra payment could be balanced. Also, inform the public about the value on new technologies. Make it transparent and informative, the public would potentially see how the benefits outweigh the extra bits of money.






Resources:
http://www.nytimes.com/2013/04/08/us/los-angeles-plan-to-turn-pollution-into-drinking-water.html?_r=0
http://www.nytimes.com/2013/02/08/us/potable-water-reuse-ideas-go-forward-in-texas-despite-concerns.html
http://www.awra.org/meetings/LosAngeles2015/doc/PP/powerpoint/SPR_S1_Villegas_Rafael.pdf
https://kbhenergycenter.utexas.edu/2013/04/10/stormwater-as-a-source-of-drinking-water-the-example-of-la/
http://www.sustainablebrands.com/news_and_views/products_design/julia_stehlin/sustainable_water_management_facilitating_global_access