Estonia receives 500 annual requests to correct well locations

Estonia’s Environmental Agency receives nearly 500 requests a year to correct the locations of boreholes shown on Land Board maps, ERR reports, because registry data often do not match reality.

One family discovered the problem when its application to install a septic tank was rejected by the Environmental Board on the grounds that the planned tank would be located where a borehole was registered. The borehole on the property was built in the 1990s in accordance with requirements and had all the necessary documents.

Timo Torp, a senior specialist at the Environmental Agency, said the agency receives around 500 requests annually to amend the data.

“We receive about 500 cases a year. We have no better way to fix the dataset than for someone to notice a problem. For example, during the design process it may emerge that there is a well with a buffer zone around it and that certain activities are not permitted. People usually come to us and ask us to make a change because the information is incorrect,” Torp said.

The Environmental Agency maintains the registry but does not itself handle location data for wells; that responsibility lies with the Environmental Board. The board said it does not keep an exact count of how many such applications it sends to the Environmental Agency.

Triin Mägi, head of the Environmental Board’s water department, said the agency was aware of the problem and received dozens of such notices and referrals each year.

“It must be understood that the registries contain tens of thousands of wells and boreholes. The volume of data that constantly needs to be reviewed and supplemented is quite large,” Mägi said.

Torp said the dataset contains about 60,000 records on boreholes, including around 40,000 records for domestic wells.

The Geological Survey of Estonia transferred its data on boreholes and wells to the Environmental Agency in 2010. Torp said the dataset was very old, with the oldest record dating from the 19th century, when measurements were not as precise as they are today.

“The problem is not so much with the current data submitted to us. It is a historical legacy that came to us when the data was transferred. Some of it comes from accounting cards dating back to the Soviet era,” Torp said.

According to Torp, errors identified through requests can sometimes be measured in a few metres, while in other cases it turns out that no borehole exists at the recorded location.

“GPS has been widely used since the second half of the last century. For everything earlier than that, the accuracy is questionable,” Torp said.

Mägi said ensuring data quality was an ongoing process.

“This is not an extraordinary occurrence. People are behind the data, and sometimes restrictions need to be displayed differently,” she said.