TURLOCK (CBS13) – The City of Turlock was on clean-up duty after an unknown individual was believed to have thrown a 5-quart can of motor oil into a community swimming pool in Columbia Park on Tuesday night, according to officials.

Upon discovering the contamination, the city called in help from the fire and environmental departments to put absorbent blankets on the water’s surface. The majority of the oil was contained in the kid’s section of the pool, though some oil was carried into the deep end through the pool’s filtration system. According to officials, a city pool contractor provided a chemical, which will run through the pool’s pumps for the next few days, to help break down the oil.

The oil contamination caused swimming lessons to be cancelled through the rest of the week with hopes to reopen by August 10 after a county health inspector tests the water on Wednesday.