Impact on communities The Atlantic Coast Pipeline is being built through low-income counties of Eastern North Carolina, and will disproportionately impact African American, Native American and poor communities, where racial and socioeconomic marginalization is occurring on a large scale. Critics say the pipeline risks becoming “a poster child for environmental racism”;  civil rights organization the National Association for the Advancement of Coloured People (NAACP) points out that this follows a long history of communities of color bearing heavy environmental burdens placed on them by the oil and gas industry. Communities on the route face serious health issues as a result of toxic pollution from industrial facilities, such as compressors along the pipeline route. In a 2016 report, Clean Water for North Carolina found that compressors on gas pipelines emit volatile organic compounds that are associated with health issues such as higher risks of cancer, birth defects and sinus problems. The closer people live to the compressors, the higher the risk of problems.

Since the beginning of the project, Indigenous people have led protests against the companies behind the pipeline for downplaying and ignoring their concerns. Families that have been resident in the affected areas for hundreds of years claim to have been misled by letters that did not sufficiently inform them about the project's purpose and impacts.

Federal court appeal Eightteen organisations and groups, including several indigenous tribes, have joined a federal court appeal by the Southern Environmental Law Centre. They state that FERC “made a mockery of the legal process," since they allowed Duke and Dominion to supplement their application for approval of the pipeline after the comment period had ended. The public was given no chance to respond. The issue has been passed on to the Economic and Social Council of the United Nations (ECOSOC) in Geneva, Switzerland, which will determine if international human rights law is being violated.

Minimal permanent jobs ACP claims that the project will bring jobs to the states through which the pipeline would run. However, ABR Alliance argues that the people hired to construct the pipeline would mostly not be local residents, but rather workers from outside the area (Allegheny-Blue Ridge Alliance). They argue that the permanent jobs created would be minimal compared to the permanent jobs lost due to disruption of business in other industries, particularly to tourism.

Greenhouse gas emissions A 2017 report from Oil Change International and BOLD Alliance estimated the annual greenhouse gas emissions caused by the Atlantic Coast Pipeline to be almost 68 million metric tons - equivalent to the pollution of 20 average US coal plants or over 14 million passenger vehicles. These emissions come from the combustion of the gas carried by the pipeline, the emission from methane (a gas with much more severe climate impacts than CO2) which inevitably leaks throughout the gas supply chain, emissions from gas extraction, compression and processing. The expansion of pipeline capacity will enable and incentivize the production of fracked gas, with grave impacts for the local communities near fracking wells and the climate more generally. The loss of forest cover (as a result of tree-clearing for the pipeline) may also contribute to the pipeline’s climate impact.

Impact on ecosystems In addition to its climate impacts, ACP would be disastrous for one of the United States' most important ecosystems. The route is set to cross the iconic Appalachian trail, horrifying those concerned with the beloved national park. Advocates highlight dangers to threatened bees, birds and bats along with other precarious species. A soil evaluation report commissioned by pipeline opponents argued that the project’s proponents are dramatically understating the potential for landslides and soil erosion. Along 38 miles of Appalachian ridgelines, between 10 and 60 feet of the mountains will be blasted and excavated to make way for the ACP. This will cause irreparable damage to ancient ridgelines, threaten mountain waterways and clog mountain roads with dump trucks taking at least 247,000 trips carrying excavated earth.

Lobbying In a report from 2016, the Public Accountability Initiative outlined the anti-democratic elements of the pipeline’s approval, including “an army of revolving door lobbyists,” “conflicts of interests at regulatory agencies,” and politicians support for industry in the context of receiving massive donations. Coverage in 2019 noted that the companies involved have spent over USD 109 million lobbying federal lawmakers and officials since the project was announced.