Jarnoltowek is small quarry in the south of Poland, with houses in close proximity (<500 m).

Annual production is 150,000 tons per year. Typical blast parameters are hole length from 10 to 13 m, hole diameter 89 mm, burden 2.3 m and spacing 2.3 m. Charge weight vary from 35 to 55 kg.

The local legislation order to measure the vibrations on the ground in front of the structure as well as inside the structure on the basement’s ground level.

Blasts were generating vibrations with the frequencies mostly in between 10 and 20 Hz. Such frequencies resulted in increased transition of the ground vibrations to the structures and claims from the owners. The quarry was facing closure of its operation. As a precaution, they have tried to blast with electronic detonators WITHOUT Austin Powder expertise and the impact on the structures got even worse.

In 2014 and mainly in 2015 a series of test blasts was done. The results indicated that there is an underground water horizon, which reflects the primary seismic waves causing the low frequencies. Sweet spot modeling was introduced to predict the vibrations with the focus on the reflected waves. The results with low frequencies were filtered out from the predictions to limit the transition to the structures. By 2016 the model was providing reliable data and assist to keep the vibration levels on the minimum, allowing the quarry to continue on its mining operation. Since that time, E*STAR electronic detonators have been used for all blasting works accompanied with Hydromite 70 explosives.