In 2017, MetaFLO’s patented technology was put to work again on a large pipeline construction project in southern Ontario. The project involved the replacement of an existing 35-km segment of 12-in. diameter pipe with 20-in. diameter pipe from the Line 10 Westover Segment Replacement Project near Hamilton, Ontario.
MetaFLO’s licensed operator Allstream Waste Solutions Inc. (AWS), developed a comprehensive plan for the onsite storage, solidification and disposal of the 1,862 m3 (> 492,000 USG) of drilling mud and cuttings generated during the planned HDD crossings. This plan included a solution to managing the waste while optimizing environmental compliance and cost savings in five key areas.
Responsibly Manage Liquid Waste Spoils in Compliance with Regulations
The project would be done utilizing horizontal directional drilling and would require the compliant management of the resulting liquid waste streams. Transportation and disposal of waste drilling fluid is regulated in Ontario, which meant land application as a liquid was not an option. As a result, disposal as a liquid would require transportation to licensed facilities. Finding an appropriate disposal site to take this volume along with southern Ontario’s congested traffic makes even a short distance a time consuming and costly trip.
Additionally, the proponents managing project operations endeavored to be compliant with proposed Ontario regulations in the management of excess soils. These regulations are intended to protect human health and the environment from inappropriate relocation of excess soil and enhance opportunities for the beneficial reuse of this important resource. This includes dry and wet, non-contaminated soils such as spent drill fluid, cuttings and hydro excavated sediment. To achieve these ends, the proposed regulation requires the tracking of all excess soil movements and the archival of data from the source to final disposal.
In order to reduce the cost of transportation and disposal, and to simplify the tracking of these waste streams, it was determined that the liquid wastes would be solidified on-site and each truck load would be tracked during shipment to a pre-determined, suitable, beneficial reuse site.
Another regulatory uniqueness in Ontario is the approval required to treat waste, known as an Environmental Compliance Approval (ECA). This approval is required for any waste treatment including mobile systems for on-site solidification of liquid waste. AWS holds a valid ECA and could provide a compliant solution.
Beneficial Reuse of Excess Soils
There are many ways to treat liquid wastes. If generating the waste is preventable that’s the best option. If it is not preventable, we’ll try to generate as little as possible. But if prevention and minimization are not possible, at least we can try to find a way to reuse that waste stream to the benefit of all stakeholders. Since most drill fluids are uncontaminated, once solidified with MetaFLO reagent, they meet clean fill criteria.
Quarries and commercial fill sites play an important role in the circular economy. The rehabilitation of operational and abandoned pits and quarries enables more sustainable local development and prevents illegal disposal of excess soil where contaminants can pose a risk to arable land and human health.
Minimize GHG Emissions
By solidifying these liquid waste streams on the job site, AWS was able to simplify the waste management process. The historic method would have meant inefficient shipments to a transfer station, as a liquid in vacuum trucks which would carry an average of 7 m3 per load. When solidified at the site of fluid generation, the mud can be shipped in tri-axle dump trucks which carry double the volume per load. Fewer trucks reduces GHG emissions, saves money and reduces risk.
By solidifying fluids on-site, the project team was able to eliminate the double handling of shipping first to a transfer station and are sending the solidified mud on a direct route to the nearest permitted clean fill facility.
On this project, our calculations show that would-be greenhouse gas emissions from shipping all this mud were reduced by approximately 58 percent. *
* Based on Argonne National Laboratory – Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) Model
Quickly Dispose of Fluid from a Site with a Small Operational Footprint
Space limitations on a pipeline right of way is always a concern. A small operational footprint for the solidification process was part of the requirements. The AWS site setup is designed to take up little space to facilitate the treatment of fluids and cuttings efficiently. With a 16-m x 1-2m footprint, situated in proximity to the drill, AWS is able to contain and process at a throughput in excess of 23 m3 per hour.
This high throughput capability proved more beneficial than expected on Line 10 as mud volumes doubled from the initial work plan.
Easily Report Operations and Compliance with Regulations to Stakeholders
The pipeline owner and general contractor had a requirement to adhere to the Ministry of the Environment and Climate Change (MOECC) excess soil framework in place pending implementation of the regulations. Allstream utilized an excess soil tracking, automated, web-based platform called SoilFLO to meet this requirement. This digital tool uses digital tickets, tracks individual trucks and compiles fully compliant trucking logs for soil tracking and data storage. Using SoilFLO, Allstream could confirm soil delivery to the pre-determined receiving site and manage hauling time to expectation for improved efficiency. Having this data available in real time on their handheld, AWS could provide the soil volume and daily loads immediately to the project GC and organized information was easily available for audit as required.