What’s in the Water? Is it an Open Source Water Quality Sensor?


Earth Journalism Network, Washington, DC

Open source technologies are revolutionizing the process of gathering data by making it more economically and technologically accessible to citizen scientists, data journalists, and those in resource poor areas.

This blog will outline several open source initiatives, currently in development, which are poised to make a big splash in water quality science.

First, we must consider some of the things open source water technologies might aim to measure. There are many measurements used to assess water quality and indicate different types of potential pollution. 

Acidity, which can indicate industrial discharges, is determined by measuring pH.  A rise in water temperature, which affects water chemistry and aquatic life, can be caused by power plants or industrial manufacturers using water as a coolant. Dissolved oxygen content, or the amount of oxygen available for aquatic life to breathe, can be affected by water temperature, flow rate, or presence of pollution.                                                                             

Nutrients need to be present for healthy water life, but can be harmful if they exceed a certain concentration. For example, excessive nitrogen or phosphorous can indicate pollution from fertilizer runoff. Presence of fecal coliform bacteria (from failing septic systems, inadequately managed animal waste, or inadequately treated sewage) is used as an indicator of bacterial presence, which sometimes poses a threat to human health. Ammonia can also be present due to water polluted with domestic sewage. In areas near mines, those concerned about water quality will want to test levels of mercury and other heavy metals.

 Water Pollution 1

Above: An example of acid mine drainage.

Measuring Metals and Microbes

An important development for measurement of heavy metals are the efforts currently underway to develop low-cost, reliable potentiostats. Potentiostats are instruments which test for microbes and electrochemically active compounds in solutions, which means that they can track heavy metal concentration in waterways. However, potentiostats for the lab normally cost several thousand dollars, are not conducive to field work, and are not practical for use by those living in resource poor areas.

CheapStat is working to change this.

Left: A used lab potentiostat for sale on E-bay for $2,400.                 Right: CheapStat.

CheapStat is a portable, do-it-yourself and easy-to-use potentiostat which can be made for under $80 using open source hardware and software.  While CheapStat does not have many of the features of commercial potentiostats, these features are often unnecessary for application of the instrument to environmental and public health issues. Among other tested applications, its developers have successfully used CheapStat to measure concentrations of arsenic in water - a problem in countries like India and Bangladesh.

Water Quality Monitoring

In addition to testing water quality, other open source efforts are underway to cheaply and easily monitor water quality. Public Lab is pioneering one such project, called Open Water, which aims to assess industrial pollution, coliform bacteria, road salt, and agricultural runoff in waterways. The project includes developing open source water quality sensors for deployment and an open water quality data platform for communities using the devices to share water quality data.

A pilot project is being carried out in the Mystic River watershed in Massachusetts, where sensors are being developed for less than $100 and tested. The sensors (called Riffles) monitor temperature, conductivity, and water depth, three parameters which are indicative of water quality issues and can help locate sources of pollution.

Below: How to Make a Riffle


Ocean Cleanup and Testing

Yet another initiative has added the goal of cleaning up pollution while facilitating water quality experiments in the ocean. Scoutbots is  the moniker of a community aiming to explore and tackle threats to our oceans (such as oil spills, radioactivity, and plastic pollution) using open hardware sailing robots such as Protei, their first recently-launched commercial prototype.

Protei is a remotely-controlled sailboat a made with shape-shifting hull capable of carrying a long, heavy payload. Protei is also modular, which means it can separate into pieces, each with a different experiment aboard.

 ProteiLeft: Protei. Photo by Cesar Harada.

The initiative appears to be progressing quickly, and aims to drastically decrease the price - from a $770 do-it-yourself component kit or a $1,280 fully assembled product - by shifting from handcrafting each Protei to a process of pre-manufacturing.

The sailboat is remote controlled by radio, Arduino, an Android phone or Iridium-enabled phone, and the hope for the future is to control it via home computer, mobile device, or any web browser.

Though these initiatives are for the most part in their beginning stages and still not widely used, they have tremendous potential  implications for public health and environmental monitoring in resource poor areas. Perhaps most importantly, they illustrate the critical role of open source, creative commons initiatives in advancing technological accessibility for the common good.