KFU hydrogeologist explains how Tatarstan’s soils protect groundwater and how to check what we drink

Scientists at the Institute of Geology and Petroleum Technologies of Kazan Federal University study human-induced changes in the Earth’s hydrosphere.

Rustam Musin, an associate professor at the Department of General Geology and Hydrogeology at KFU’s Institute of Geology and Petroleum Technologies, has spent more than 30 years examining how Tatarstan’s groundwater system forms and changes, from springs and wells to deep aquifers.

Oil production, agriculture and industry are commonly viewed as the main threats to groundwater. But how great is their actual impact? Musin addressed this question in a series of articles published in 2026, presenting the results of geoecological studies in several parts of Tatarstan, including oil-producing areas.

After studying the region’s soils and sediments, the geologist concluded that they have a strong natural immune system against pollution: clay-rich rocks adsorb contaminants, infiltrating water dilutes them, and microorganisms break down organic matter.

“Across most of the Republic of Tatarstan, the geological environment has substantial buffering, or protective, properties. First, clay layers beneath the soil act like a sponge: they absorb and retain contaminants, preventing them from moving deeper. Second, the terrain is dissected by ravines and river valleys. These provide short routes through which groundwater quickly reaches the surface, before it can accumulate a large amount of pollution. Third, part of the rainfall and snowmelt – 15 to 20 percent of total precipitation – percolates into the ground, diluting substances already present there. Finally, many pollutants are organic and are gradually degraded by chemical reactions and microorganisms. All this means that, under moderate human pressure, contamination of fresh groundwater tends to remain local,” Musin said.

Oil-producing Southeast

Southeastern Tatarstan is the republic’s main oil-producing area and experiences the greatest industrial pressure. There, chloride contamination of fresh groundwater has been identified across extensive areas, reaching high levels in some locations, the expert said.

“Since the 1990s, Tatneft has carried out environmental-protection measures that have largely stabilized the hydrogeochemical regime and reduced the intensity of contamination. Self-purification processes are also widespread at depleted production sites,” Musin said.

He added that the company has improved popular springs, installed small water-treatment stations to provide household drinking water to settlements, and financed hydrogeological studies to identify freshwater groundwater deposits. Some of these deposits have already been developed—or are planned for development—to supply towns and villages in the region.

“The once-acute problem of drinking-water quality in the southeast of the republic is gradually being addressed, although a full solution will take time,” he said.

Local and regional risks

According to Musin, many factors can contaminate groundwater. Their scale and intensity depend on the balance between the geological environment’s natural buffering capacity and the type of human impact.

“At present, the effects of road traffic and the use of de-icing salt are local. Agriculture and industry have a broader impact, although its intensity varies sharply,” he noted.

For example, in Tatarstan’s Cis-Volga region – covering about 10,000 square kilometres – the intensive use of mineral and organic fertilizers in the 1990s and 2000s had virtually no effect on groundwater quality, except near poorly equipped fertilizer-storage sites.

Musin also said that the industrial-waste disposal facility operated by Nizhnekamskneftekhim since 1982 has almost no detectable effect on surface or groundwater at distances of around 1.5 kilometres in the direction of groundwater flow.

Within the Nizhnekamsk industrial zone, which includes Nizhnekamskneftekhim, Nizhnekamskshina, TAIF-NK and TANECO, drinking-quality water can be obtained even directly on industrial sites, provided that the intake screens of water-supply wells are installed at depths of 150 to 180 metres, he informed.

Deeper aquifers are better protected

Shallow groundwater is the first to be exposed to contamination. More deeply buried groundwater, however, may retain good drinking quality even beneath urban development and industrial facilities.

“Natural conditions lead to a gradual increase in mineralization with depth. In flat regions, the interval containing fresh groundwater suitable for household drinking-water supply rarely exceeds 300 to 400 metres. In Tatarstan, it reaches 300 to 350 metres, although the prevailing values are up to 200 to 250 metres,” the associate professor explained.

Kazan currently receives water from two sources: 92 percent comes from the Volga River, while the remaining 8 percent comes from underground sources. This balance could change in the future.

“Underground sources are more reliable. In the 1990s and 2000s, three freshwater groundwater deposits were identified and evaluated for Kazan’s municipal drinking-water supply: Zelenodolskoye, Stolbishchenskoye and Laishevskoye. Their combined reserves are about 600,000 cubic metres per day,” Musin added.

These deposits have not yet entered operation. Projects are now being prepared to develop the Stolbishchenskoye deposit.

How to test drinking water

Musin also offered practical advice on testing drinking-water quality.

“Take a sample in a clean glass or plastic container with a volume of 1 to 1.5 litres. Rinse the container beforehand with the water being sampled, then deliver it to an accredited laboratory. There are many water-testing services available online today,” he said.

He recommended first assessing key general indicators:

• Total dissolved solids, or mineralization
• Total hardness
• pH
• Permanganate oxidizability, an indicator of oxidizable organic matter

Depending on the situation, testing may also include:

• Organoleptic characteristics: odour, colour and turbidity
• Nitrogen compounds: nitrates, nitrites and ammonium
• Microbiological indicators
• Heavy metals, including lead, arsenic and cadmium

Testing every parameter is difficult and expensive. He therefore advised residents to contact the local sanitary and epidemiological service to determine which water-quality indicators most often exceed permissible levels in their area, then request testing for those specific substances.

The KFU expert also encouraged households to learn about domestic water-treatment methods. One option is partial freezing followed by consumption of meltwater. However, Musin cautioned that producing physiologically balanced meltwater requires knowing the initial water’s mineralization, which should not be high, as well as controlling the extent of freezing.