The spill has dealt a blow to tourism in the popular resort, and to businesses who make most of their money in the summer season.
"There were many people until Sunday; the stain arrived on Monday, and since then, no one is swimming anymore," said 48-year-old Richard Gutierrez, who has a food and soda stand on Miramar beach.
"We cannot sell anything, there are no vacationers, there is no one" apart from about 100 cleanup workers -- soldiers, Repsol hired hands and volunteers -- removing the polluted sand with spades to be taken to a toxic waste treatment facility.
Peru's government has declared the spill of some 6,000 barrels of oil an "ecological disaster" and has demanded compensation from Repsol.
The company denies responsibility, saying maritime authorities had issued no warning of freak waves after the Tonga eruption.
The task, which began Tuesday, is an arduous one.
The workers deposit the polluted sand onto blue tarps, which are dragged to a pile further inland, awaiting removal to another site.
Work begins at 8:00 am and finishes at 6:00 pm, with a 30-minute break for lunch.
No one knows how long it will take to clean up the affected stretch of coastline, but in Miramar, it is estimated it will last at least two weeks.
The environment ministry said 174 hectares -- equivalent to 270 football fields -- of coast were affected, and some 118 hectares at sea.
Marine currents have dispersed the oil all the way to the coast of Chancay district, more than 40 kilometers from where the spill occurred.
The health ministry has identified 21 affected beaches and warned bathers to stay away.
The spill has also affected hundreds of artisanal fishermen who operate on the central Peruvian coast.
They rely on catches of sole, lorna drum and Peruvian grunt -- fish commonly used in the local delicacy ceviche, a marinated raw fish dish Peru is famous for.