Minister for the Marine Noel Dempsey is preparing a series of safety measures on the Corrib gas onshore pipeline in tandem with publication of a final review of the structure.
However, the Minister said that no further consents will be issued for the pipeline until Shell E&P Ireland submits a revised application, based on recommendations in the new review.
The final report on the pipeline by Advantica Consultants, and recommendations drawn from it by the Minister's Corrib technical advisory group (TAG), are expected to be published this week and possibly as early as tomorrow, according to sources.
Advantica was the third in a series of consultancy companies hired by the Minister to look into safety aspects of the project and it held a public hearing in north Mayo last October. The hearing was boycotted by the "Rossport Five" and supporters over the limited terms of reference.
It is expected that the documents will endorse the key recommendations in the consultants' draft report, published late last year. However, they will be "modified" by certain issues raised, the Minister said.
In that draft, the consultants recommended limiting pressure in the pipeline to a maximum pressure of 144bar to enable it to be reclassified as a "class 2" suburban pipeline.
They also recommended provision of a formal integrity management plan and an independent audit and inspection procedure, and called for a review of the consent and permission system by the Minister's department.
The Shell to Sea campaign criticised the consultancy study for failing to address the central issue of proximity of the pipe to people's homes in Rossport.
Shell E&P Ireland accepted the "principle" of limiting gas pressure, but took issue with a number of points, including the possible emergence of the contaminant hydrogen sulphide or "sour gas" in the Corrib system.
"I don't think anyone will be surprised at the general thrust of the recommendations in the draft report, but there are changes based on some of the evidence that was given," Mr Dempsey said. "In some cases, there will be elaborations and clarifications from the Corrib technical advisory group. I want the picture on the safety element of this to be as clear as it possibly can be for everybody."
The Minister said that as part of his monitoring of the Corrib project, pipes would be examined by his officials. Shell to Sea published photographs last week of pipes imported for the project four years ago which appear to be rusting in storage in Killybegs, Co Donegal.
The Minister said that Shell had informed him that the company had been refused access to treat pipes to prevent corrosion, but acknowledged that this related only to north Mayo and not to Killybegs.
"The integrity of the pipes will be a concern for us, and TAG will be inspecting pipes before they will be allowed to be used again," Mr Dempsey said.
Shell E&P Ireland said that the pipes had "oxidised" naturally, and observed corrosion of the "high quality steel" was "superficial". The condition of some of the plastic end caps had deteriorated, the company said.
However, regular ultrasonic inspection had confirmed that "despite this surface colouration, the wall thickness of the pipes remains above the required specification". The pipes would be subject to regular inspection, and will be cleaned before use, the company said.
Shell to Sea campaigners offered glasses of drinking water from Carrowmore lake in north Mayo to staff at the Environmental Protection Agency in Dublin last Friday. The campaign says that the lake is heavily contaminated with aluminium as a by-product of Shell's presence in Bellanaboy, site of the Corrib gas terminal. This is disputed by Mayo County Council.