In the 18th century, the identification of contaminated waters was based primarily on basic observation, common knowledge, and sometimes trial and error. The understanding of waterborne diseases and the notion of environmentally harmful microorganisms were not well established at the time. However, some methods and signs have been identified that indicate water quality issues:
Observation of color and smell:
In the 18th century, people often relied on their senses to detect possible water pollution. If the water was an unusual color, such as cloudy or discolored in appearance, or had an unpleasant odor, this was considered suspicious and should probably be avoided.
Taste testing:
While not the most reliable method, taste testing is sometimes used to assess water quality. If the water tastes strange or unpleasant, this could be taken as a warning sign.
Health Effects Observation:
People discovered that drinking water from certain sources led to an increase in diseases such as cholera, dysentery and other gastrointestinal problems. These eruptions were often linked to a specific water source, suggesting that the water was contaminated.
Knowing Local Sources:
In many communities, some water sources have been safer or more reliable than others. This knowledge was often passed down from generation to generation, and people avoided water from sources suspected of being contaminated.
Avoid water near polluting activities:
People knew that water near sewers, animal waste, or other pollutants could be more susceptible to disease. Therefore, they often refrained from using water coming from those places.
Boiling Water:
Although not a method of identification, boiling water was a common practice to make drinking water safer. Although people may not know exactly why it works, they have found that boiling water before drinking reduces the incidence of waterborne diseases.
It should be noted that the scientific understanding of water pollution and the role of microorganisms in causing disease only emerged in the late 19th and early 20th centuries thanks to the pioneering work of scientists such as Louis Pasteur and Robert Koch. Before that, knowledge and methods for identifying contaminated water have been based on observations and empirical experience.