WASHINGTON (AP) — The National Park Service is trying to remove a thick layer of green algae from the reflecting pool in front of the Lincoln Memorial less than a month after a $34 million overhaul was completed.

The algae and scum covered one end of the reflecting pool Friday. Workers were using nets to try to remove it.

The reflecting pool was just reengineered during a two-year project to draw river water from the Tidal Basin instead of city drinking water. The system is supposed to filter and circulate the water to keep it cleaner than in the past.

Park service spokeswoman Carol Johnson says the new water system is complex and needs to be fine-tuned. She says workers are boosting the amount of ozone in the water to improve the quality.

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