La Atarjea is a water treatment plant located in El Agustino, a district of Lima, Peru.

La Atarjea was originally a spring located in the eastern outskirts of the city of Lima, behind Presbítero Maestro Cemetery.

[1] People from Lima drank their water straight from the Rímac River until 1552, when local authorities began looking for alternate sources.

[2][3] On December 24, 1953, a freight train of the Ferrocarril Central Andino headed for Lima derailed next to the area, killing seven people.

[4] In 1955, the government of Manuel A. Odría signed a contract with Degrémont in order to construct a proper treatment plant in an 11-month period with a capacity of 5 m3/s, the largest of its time.