In Káraný, one of the most critical water supply areas providing drinking water for Prague and the surrounding region, an accident occurred in 2024 at historical artesian well E, originally drilled in 1902. During the removal of an operational manhole, a concrete foundation fell onto the cast-iron wellhead, damaging the casing structure at a depth of 8.5 m and triggering an uncontrolled groundwater overflow of up to 30 l/s.
Subsequent CCTV inspections and archival research revealed that the well had not been properly sealed in the past. Remediation was carried out jointly by Photon Water Technology, Ekodrill, and PVK (Prague Water and Sewerage company). The procedure included removing the damaged DN 225 cast-iron casing, stabilizing underground caverns with gravel backfill, and performing multi-stage grouting with a plate packer. A total of 14 metric tons of gravel and 11.2 metric tons of cement (28 m³ of grout mixture) were consumed, exceeding the initial estimate more than threefold.
The operation successfully restored the hydraulic tightness of the artesian confining layer and prevented further surface leaks. The incident underscores the necessity of a professional hydrogeological approach when dealing with legacy water structures.
We provide comprehensive services for water resources: design and engineering services, well drilling, diagnostics (CCTV inspections, pumping tests), monitoring, rehabilitation (air-lift, ultrasound, chemical cleaning), and professional well decommissioning in compliance with legislation and standards.
