Bare Necessities

What do we value about our natural resources?  A survey of residents in a Mississippi gulf coast county in 2003 indicated strong incentives to maintain good water quality in rivers, bayous, and the waterways leading to the Gulf of Mexico.  Last summer, the importance of this natural resource was reinforced following the devastating oil spill.

The Hancock County Greenways project undertook a survey of community conservation values in April 2003, with eight goals.  These are listed in order, as respondents ranked them from highest to lowest importance:

1 protect water quality streams/wetlands

2 protect wildlife corridors and native habitats provide recreation areas

3 preserve scenic views

4 keep land in undeveloped natural state

5 protect floodplain areas

6 preserve agricultural or forestry land

7 preserve archaeological and cultural resources

We also recorded the reported use of recreational facilities in the county, with the beach walking/biking path identified as the most popular, a neighborhood bike path as the second most highly used, and playgrounds, hiking trails, and waterways in quick succession.  Many people responded with recommendations for additional recreational uses, including more biking paths, tennis courts, and a community swimming pool.

One of the most popular requests was for restrooms along the beach.  The county provides portable toilets at the beach parking areas.  Restrooms with showers would provide a place for families with children to come from a neighboring community and spend the whole day, first on the beach, then walking through the shops downtown, and staying for dinner.  Without a shower and a change of clothes, we found that people cut their visits short, and thus reduced the economic benefit to the county. 

The lack of permanent facilities also impacts water quality.  Many people shy away from portable restrooms, preferring to use the water for most (non-solid) necessities.  The lack of a facility to wash hands after toilet use may also have impact on water quality.  There were concerns about permanent restrooms too, that they would become havens for undesirable drug dealers, homeless, and others; and encourage camping on the beach.  These are public safety issues with merit, but the solutions lie in enforcement of existing laws.

After the unnatural disaster of 2010, we need to reconsider the importance of what enters our waterways.  Any opportunity to improve the quality of water, from reducing pesticide and fertilizer use upstream to ensuring dog owners clean up after their pets, may help keep the beaches open and recommended for human use.  After the terrible impact on our coastline, we must do all that is within our power to maintain the natural systems, so that when the unexpected occurs, there remains some capacity in the system to counter new threats.

Choreographing Water in the Built Environment

Water, simple and necessary, threatens vulnerable citizens throughout the world.  The need for safe drinking water is severe.  There are two obstacles to providing clean water: the “inadequacy” of local supplies, and the presence of contaminants.  How can better design find solutions to this growing problem?

There are often seasonal differentials in water supplies, when excess precedes drought.  The ability to find and store water was essential to human development, with the discovery of how to find and protect water sources, and how to keep water in every size of vessel from a clay pot to a reservoir.  Human life requires a minimum of 1 liter of drinking water per person, per day.  We use much more: the average citizen in the U.S. uses 575 liters/day, a citizen of India uses 135 liters.

Public water distribution systems allow many the luxury of forgetting the drudgery of collecting, transporting, and storing water.  In places without reliable infrastructure, collecting water requires significant time and energy that could be spent by children studying at school, or by women at work. 

Extending infrastructure to serve all people comes at a high cost.  In urban areas with high densities, this cost is borne by the great number of people.  Rome constructed nine aqueducts by the year 52 to provide water for a population of nearly one million.  Roman engineering not only provided the distribution system but built storage to guard against evaporation, interruption, and defilement.  The basilica cistern in Istanbul is a wonder of architecture with carved capitals and vaulted ceilings, constructed to house only water.

Massive engineering projects of the last 100 years include hydroelectric dams and channelized water, resulting in long-term environmental degradation.  These community-scale “solutions” harmed natural cycles, but direct new efforts to site-scale, self-sufficient alternatives that capitalize on existing technologies and products.

Streets and buildings may become the new aquifers to collect and store water.  In urban areas, green spaces may be “manufactured” by reclaiming and transforming brownfields and impervious edges along streets.  Green boulevards enhance the aesthetic quality, and also collect, filter and store stormwater in swales, restoring water to the aquifer through groundwater recharge and to the atmosphere through vegetation.  Options to impervious surfaces for roads and parking are growing with pervious concrete, interlocking pavers, grasspave or gravelpave systems.  In addition, green boulevards cool the microclimate and reduce the heat island effect.

Construction of waterworks is incomplete without purification.  A number of techniques are available to remove contaminants using physical processes (filtration), biological processes (microbes), chemical processes (chlorination), and electromagnetic radiation (exposure to UV light).   These techniques are resource-intensive and require community-scale facilities to remove solids, salts, organic pathogens, and toxic ions.

One promising technique is solar disinfection using plastic bottles exposed to direct sunlight.  UV wavelengths react with oxygen dissolved in the water to produce hydrogen peroxide that damages pathogens and destroys cellular structures of bacteria.  The use of titanium dioxide film over glass cylinders in conjunction with solar disinfection took only 15 minutes on a sunny day to render coliform bacteria undetectable in trials, and the water remained free of bacteria for seven days. 

When UV radiation is not available due to rainy weather, rainwater harvesting may be employed.  Most buildings have some form of rainwater collection: gutters, roof drains, scuppers, and downspouts.  These building elements are an asset for collecting rainwater; all that remains is the storage component.  Project-scale collection systems collect, channel, treat, and store rainwater on site until needed by the building users.  South-facing metal roofs overlaid with TiO₂ glass tubing can collect, purify, and store rainwater for potable water.  This system has the added benefit of providing hot water, lowering energy use.

And finally, not all water has to be treated to drinking water standards.  Rainwater and greywater captured from showers and sinks may be used for flushing and irrigation.  Buildings may repurpose “used” water for non-potable functions; this slightly used resource offers a measurable contribution to the global water cycle, the endless connection between vapour and beverage, droplet and sea.