Geodesign Session 4 Water Sustainable Practices SD and No Baja
There are several different directions that our planet can take to address the ever growing need for water and energy. This will involve integrating technologies of a large and small scale into our grid and into our homes as well. There are two main technologies in which to address large scale water sustainability: desalination and ‘pure water’ recycling. As the California dries out, it is increasingly important to adopt proven strategies to maintain the current standard of living. The effectiveness of these strategies is instantiated by the ability of countries like Saudi Arabia and Israel to endure perpetual drought successfully.
The most common type of desalination is multi-stage flash, but is the least energy efficient. Reverse osmosis, a stringent physical filtration process, is the method of choice in the Carlsbad and Santa Barbara desalination plants. Reverse osmosis has allowed countries like Israel to source 40% of their water from desalination. By 2050 they hope to get as much as 70% of their water from the ocean. There are some concerns about the effects of its brine byproduct on the local ecosystem, but the vast benefits including new jobs, fiscal savings, and access to fresh water outweigh them.
The other successful practice in Israel is waste water recycling, which allows for over 80% of its wastewater to be reused as potable drinking water. Water recycling operations are staged in select regions of the United States, but there is virtually no reliance on them. Companies like Pure Water are emerging in California in tandem with growing water scarcity. Water purification utilizes multiple stages of cleansing which leave the final product completely pure of any impurities. These processes include but are not limited to reverse osmosis, membrane filtration, advanced oxidation, and exposure to UV radiation with hydrogen peroxide. The process is so thorough in order to ensure that the water supply remains up to acceptable water standards.
The latter half of the water presentation divided best practices by long and short-term timeframes. The most effective short-term strategy is urban water use efficiency. Immediate solutions in California generally mean water cutbacks in agricultural districts. These water restrictions have massive economic trade offs that many consider to be too steep a cost for water conservation. Urban water use efficiency is far less controversial because it has comparatively minimal impact on California’s economy. The main hurdle for the government and utility companies is mobilizing the public. California has issued water use caps in each water district in addition to penalty by fine if the limit is exceeded. The stated emphasis is to succeed in reducing water consumption, not to collect overuse fees.
The best long-term strategy also deals with urban water use, but more specifically prescribes recycling. This strategy adds local efficiency to homes and businesses rather larger systems like those found at Pure Water. Grey water systems are installed below ground and handle waste water from showers, bathroom sinks, and laundry machines. After filtration treatment grey water can be used for irrigation, toilet water, and industrial processes if applicable. Unfortunately, these systems are expensive and may not offer substantial water savings if applied to only one structure. The most effective way to implement grey water technology is in groups. For example, a mixed residential and commercial area could combine and channel waste water to a single high capacity tank for treatment and distribution. According to 2013 study published in Sustainability a shared system is the most economical method with optimal water savings potential.
After a long history of reliance on fossil fuels, developed countries are diversifying their energy matrices. Germany, Spain, and Italy are the biggest adopters of renewable energy overall, but the United States is among the top 5 implementers of solar, wind, geothermal and biomass generation. China is the current leader in wind generation and one of the top 5 in solar and biomass generation. Wind and sunlight occur passively and abundantly, so utilizing them is a matter of capture and transmission. Fossil fuels on the other hand require extraction, refinement, transport, and combustion. Environmentally renewables are a no-brainer. Economically they can be troublesome. A massive amount of financial capital is required not only for research and development of new technologies, but also to build facilities, individual units, and systems. The emergent renewable companies are forced to compete with a technologically and economically mature fossil fuel industry, so to survive they need government subsidy to artificially support them until they can establish an independent presence in the market. Free market competition between big oil and green tech would ensure a continued fossil fuel monopoly over energy. Subsidies for R&D and incentive for consumer adoption is a key component of making renewables economically competitive in the short term energy market.
Other unique renewables loosely grouped as bioenergy uses sugarcane, corn, palm oil, algae, or even organic landfill waste to produce bio gas, diesel, and ethanol. While renewable energy production is a keystone issue, a sustainable future must also include more efficient use. For example, recycling aluminum uses 95% less energy compared to mining it. Recycled glasses, paper, and plastic also offer substantial energy savings. There are actually many ways to improve energy efficiency in everyday life: proper insulation and window sealing can noticeably reduce use of heating and cooling systems. More advanced household solutions like UC Berkley’s duct sealing technology uses an aerosol as filler in multi-layered windows to further reduce indoor temperature changes. Finally, new buildings can easily be equipped with energy saving features like natural lit or “green” roofing to reduce energy consumption and minimize heat radiation respectively.