In many cases, only a clear change in the color, smell, or taste of water is reminiscent of the need for maintenance.
In Finland drinking water is obtained from an estimated one million wells. Most of the wells can be found in summer cottages, but well water is also drunk in hundreds of thousands of Finnish homes. The majority of the owners of the well neglect the maintenance measures of their well – be it a cottage or a home well, says an expert from the Finnish Water Association’s diffuse water supply department Pertti Virtanen.
“The nationwide well water survey dates from 1993. At that time, 80 percent of Finnish wells were in poor condition. Now, after 27 years, I can say that the situation has not changed much. The wells are forgotten, ”says Virtanen.
According to Virtanen, the well is easily taken for granted, and often only a clear change in the color, smell or taste of the water wakes up to find out the condition of the well and the quality of the water.
Health and a senior researcher in the microbiology unit of the Department of Welfare (THL) Ilkka Miettinen according to the condition of the well should be checked annually. For the inspection, a visual assessment of the internal and external structures of the well and the terrain surrounding the well is sufficient.
The terrain should run away from the well. It is typical that, for example, the manhole cover may start to leak. Then rainwater, melting snow or possibly even small animals can enter the well. After repairing the cover, the well should be thoroughly cleaned.
If no clear defects are found in the mine or well water, according to Pertti Virtanen, it is sufficient to perform maintenance maintenance on the well every four years: pressure washing, sludge removal, vacuuming and sand and lime replacement.
“Over time, deposits form on the structures and bottom of the well, which are good breeding grounds for microbes. If the well is not cleaned regularly, the deposits will start to show up somewhere in the quality of the drinking water, ”says Virtanen.
THL: n special designer of the microbiology unit Outi Zacheus recommends that the quality of the well water be examined every three years or more frequently if there is a change in odor, taste or color in the well water. It would also be important to determine the water quality whenever a new well is commissioned.
According to Zacheus, metals such as iron, manganese or fluoride, for example, can be dissolved in the well water from the soil. Manganese is harmful in large quantities, especially to children. It has been found to be associated with learning and behavioral disorders in children and fine motor clumsiness.
High levels of iron, on the other hand, can irritate the stomach. Wells with a lot of iron often also have a lot of manganese. High doses of fluoride, in turn, are detrimental to teeth and bones.
According to Pertti Virtanen, faecal-derived bacteria may also be found in the well water, which has accumulated a lot of sediment. They can be a health risk, especially for the terminally ill and the elderly.
“It is good to remember that colorless, odorless and tasteless water can be unfit for drinking, so regular well water tests should not be forgotten,” Virtanen emphasizes.
Well water is formed within a radius of a few tens of meters from the well, usually on the upper slope. If there are changes in the soil near the well, it is worth monitoring the situation in the well, says Virtanen.
For example, if roads or sewage systems are built in the area or fertilizers are applied, they can affect groundwater.
“In recent years, cases of compost mold have been spread on the site, and groundwater has also been contaminated. Everything that is put in the well water formation area travels with the rainwater to the groundwater and through it also to the well water, ”Virtanen says.
According to him, about 30 percent of Finnish wells are boreholes. The rest are mainly tire wells. According to Virtanen, there is too little talk about the disadvantages of boreholes.
Groundwater is usually of the best quality at a depth of about five meters. Boreholes, on the other hand, often reach a depth of one hundred meters, in which case the well water can be up to a thousand years old, according to Virtanen. In the five-meter-deep ring wells, the water is no more than a few months old.
“At worst, radon, arsenic or uranium, for example, can be found in boreholes, with significant health risks. However, all types of wells have their own pros and cons and it is worth comparing them already in the planning phase of water supply, ”says Virtanen.