Plans to replace a pipe that delivers aviation fuel to Heathrow and Gatwick airports could damage a national park, its governing body has warned.
Esso has proposed routes for a new pipeline from Fawley oil refinery near Southampton to a facility at Hounslow.
It said the existing pipe, built between 1969 and 1972, was coming to the end of its life.
The South Downs National Park Authority said the project could threaten woodland and historical sites.
At a meeting discussing the authority's response to Esso's public consultation, environment strategy officer Roni Craddock said: "There is potential for permanent damage to the national park."
She said woodland, hedgerows, sunken lane banks and undiscovered archaeological features could be at risk.
She added: "Looking at the route options which Esso have consulted on, my feeling is that they have done their homework and they have revealed many of the issues that we would have raised."
Policy officer Andy Beattie said he accepted that some of the new route should roughly follow an existing pipeline through the park from Lower Upham to West Tisted.
But he recommended changes to proposed sections near Chawton and through Alice Holt Forest to reduce the impact on the park.
As part of its response, the national park authority called on Esso to "produce a costed scheme of mitigation and compensation before selecting its preferred route."
Esso is proposing to replace a 90km (56 mile) section of pipeline between Boorley Green, Hampshire, and its West London Terminal storage facility.
It previously replaced a shorter span between Boorley Green and Hamble in 2002.
It said the existing pipeline kept "around 100 road tankers off the road every day".
Project executive Tim Sunderland said: "Our aim is to carefully design the pipeline to avoid or reduce environmental impacts.
"The Authority's officers have expressed satisfaction at our assessments to date."
The firm's consultation on proposals for a number of potential routes lasts until the end of April.
Its preferred route is due to go before the Planning Inspectorate at the end of the year.
If approved, construction work could start in 2021.