The dumping of the fill in an erosion gully off Brooklands Road in Wallaroo had been vehemently opposed by local residents who engaged an eminent soil scientist, acoustics engineer and legal opinion in an effort to head off the proposal.

Residents are distressed over how the proposal will affect the amenity of their quiet, semi-rural environment.

In his investigations, respected sound engineer and consultant to Transport NSW, Glenn Leembruggen, found that he considered "these noise levels constitute an unacceptable loss of amenity ... [and] the increase in noise is contrary to the aims and objectives of the Yass Local Environment Plan".

In its debate over the proposal, the outgoing council said it had peer reviewed the extensive documentation provided and requested the applicant provide a revised site plan and engineering drawings to address the residents' concerns.

The heated discussion around the transport of large volumes of fill in and around the region comes at a time when the ACT government is preparing a works proposal for the second stage of its light rail project, which will require 60,000 tonnes of fill to be trucked into the heart of the territory to raise London Circuit.

The movement of fill around the region and mostly over the ACT border into NSW, much of it generated by commercial construction activity inside the territory and dumped illegally, has long been a source of irritation to regional councils surrounding Canberra, with residents alarmed over how the dumping has continued with impunity.

Waste from territory projects has been trucked over the border for years because of the high cost - $12.80 per tonne - of dumping it within the ACT. By the Yass Valley Council's own admission, this most recent proposal will also wreak even more damage to regional roads already potholed and broken up by recent heavy flooding events.

As Councillor Geoff Frost, who is not standing for re-election after three consecutive terms, told the final meeting on Wednesday: "we do not have the capacity to stop this material coming over the border ... but we have the capacity to influence this proposal".

In an extensive report into the Wallaroo dumping proposal, soil and water management expert Andrew McLeod found a number of major issues including risk of contamination, damage to existing trees and biodiversity, and the potential for further damage without a proper erosion and sediment control plan.

Opponents of the dumping plan are appalled by the council's decision and believe it is in clear contravention of the Yass Valley Local Environmental Plan.

The number of heavy truck movements - a problem mirrored in Canberra's light rail proposal - poses a major issue.

Thousands of truck movements - ranging from 22.5 to 33-tonne truck and dog tippers - are planned on the Wallaroo rural roads generally frequented by school buses and light vehicles, and not designed for large volumes of heavy trucks.

While the council will limit truck movements to 10 per day in each direction and restrict operations for between 9am and 4pm on weekdays, residents say this will extend this single dumping program in their local community for years and create ongoing noise and road safety issues.

This year the council adopted a new heavy haulage plan to recover the cost of road damage caused by heavy vehicles but the Brooklands Rd dumping plan, because it had been filed earlier, doesn't sit within that requirement. Instead, the applicant is required to pay just $6985 in compensation for using the road network, although a voluntary contribution has been separately negotiated.

The council's own planning has found that the cost of damage to its road is likely to exceed $450,000.