# Line 5 restart slips to September 6-8 as crews switch from flaring to compressed air

> Ten days into the Iron County shutdown, Enbridge has moved its return-to-service window back by up to three days and changed vapor-removal method at the excavation. Wisconsin health officials have now reviewed the air data and found no concern outside the evacuation zone but an elevated long-term benzene reading inside it. PHMSA still holds the site; the state DNR is still waiting at the fence.

- Label: Fact
- Type: News item
- Published: 2026-09-04T09:00:00+04:00
- By: Winda Beacon newsroom
- Topics: Pipelines
- Canonical: https://beacon.winda.ai/news/2026-09-04-line-5/

## Where it stands

Line 5 shut since August 25; Enbridge now targets return to service September 6-8, an operator estimate, moved from September 5. Compressed air injection began September 2 at the excavation; water monitoring wells installed, sampling results pending. Wisconsin DHS: no health concern outside the evacuation zone, elevated long-term benzene risk inside it. PHMSA has still not authorized DNR access. Status: investigation_ongoing.

## What happened

Enbridge's September 2 update, posted at 6:31 p.m. CT, records two changes at the Sitan Road site. First, crews began introducing compressed air to the product remaining in the valve excavation to evaporate and disperse it, a shift from the nitrogen-and-flare approach used on the isolated one-mile segment since August 30, per Enbridge's incident statements. Second, the operator's return-to-service goal moved from September 5 to a September 6-8 window, per Enbridge; WPR reported the revised target on September 3. Water monitoring wells have been installed and sampling is under way, with results expected soon, per Enbridge. The evacuation zone and the Iron County Sheriff's no-fly order remain in force, and air monitoring continues to read safe outside the zone and where crews work, per Enbridge. As of the weekend, roughly 2,000 barrels, about 84,000 gallons, of liquid remained in the excavation, per WPR citing Enbridge; the 31,000-barrel vaporized volume is unchanged. Beacon holds the story at investigation_ongoing: PHMSA is the lead agency and no finding has been published.

The state layer moved on two fronts on September 3. The Wisconsin Department of Health Services said its review of the monitoring data found no evidence of health concern outside the evacuation zone, with propane and isobutane below explosion-risk levels and benzene below short-term health thresholds, but it flagged an elevated long-term benzene risk inside the exclusion zone and said only cleared personnel in appropriate PPE should enter, per WPR. DHS also said it supports more monitoring inside and outside the zone. Separately, WPR reports that reroute construction has resumed after the 48-hour stand-down that began August 31, with about 700 workers on the project and roughly two-thirds of the 41-mile reroute built. The DNR remains unauthorized to enter the site, per WPR, so its groundwater, soil and surface-water assessment still waits on PHMSA, which is investigating the incident including any violations of federal pipeline safety regulations, per WPR. Two facts remain on the record as context in time order, not as findings: the reroute has drawn four prior DNR notices of noncompliance, all resolved, per WPR, and the strike occurred on a segment exposed for valve work. Which excavation-damage controls were in place is PHMSA's question to answer.

**Analysis:**
## What it means

The switch from flaring to compressed air is the tell: this restart is being managed for public optics as much as engineering. For operators, the lesson is that visible mitigation choices now shape regulatory goodwill; for investors, every slipped restart date on a contested line reprices shutdown risk.

## Sources

1. Enbridge incident statements
2. Wisconsin Public Radio
3. Wisconsin DHS (via WPR)
4. Wisconsin DNR
5. Federal Register
6. PHMSA newsroom
7. Beatty & Wozniak
8. Great Lakes Now
9. ICT

Published by Winda Beacon (https://beacon.winda.ai).