When a public authority says, “We need a new landfill cell,” behind this simple request lie dozens of categories of work that must fit together perfectly. If one is missing or is poorly executed, the entire landfill risks failing inspection. This article explains, step by step, how to properly construct a non-hazardous waste storage cell, based on direct experience from Cell 3 of the Ghizela Landfill in Timis County.
What does a compliant landfill actually mean?
In Romania, non-hazardous waste landfills must comply with two key regulations: Government Decision 349/2005 on waste disposal and MMGA Order 757/2004, which establishes the technical standards for landfill operations. Together, these regulations define the protective systems that must be included in any new or expanded landfill cell.
The term “compliant” is not merely a formality. It means that the landfill has certified technical systems in place to prevent soil and groundwater contamination, that leachate is collected and treated, and that the site can be properly rehabilitated upon closure.
DEFINITION: RUNOFF
Runoff is the liquid formed when precipitation water passes through a mass of waste, carrying dissolved or suspended substances. It is a potentially severe pollutant for the water table and must be collected in a watertight basin, from which it is transported to an authorized treatment facility.
The 4 categories of tasks performed by a storage cell
At Cell 3 of the Ghizela Non-Hazardous Waste Landfill in Timis County, the joint venture INOVECO SRL (lead contractor) – ALCONS ENGINEERING SRL is carrying out the following types of work for the Timis County Council. Base area: ~9 ha. Fill height: 20 m.
1. Earthwork and landscaping
The base of the cell is constructed in ridges, with cross slopes of at least 2% toward the leachate collection pipes. If the bottom of the cell were flat, leachate would accumulate on the geomembrane, exerting hydrostatic pressure.
- Modeling the cell bottom to the designed dimensions (ridge profile)
- Construction of perimeter dikes with sloped sides and compacted crowns
- Laboratory tests (modified Proctor test)
Phased quality inspection — required prior to the installation of geosynthetics
ATTENTION: HIDDEN WORK
Earthworks are a hidden phase. Once covered with geosynthetics, they can no longer be inspected without dismantling the entire system. A quality inspection must be conducted before proceeding to the next phase of work.
2. Geosynthetic Sealing System
This is the feature that most clearly distinguishes a compliant warehouse from a non-compliant one. The system consists of three layers (from bottom to top):
Why three barriers? The principle of redundancy. The GCL acts as the first line of defense and self-seals if the geomembrane is punctured in a localized area. Together, they provide the protection required by European legislation.
Why use textured geomembranes on slopes? The textured surface increases the adhesion between the geomembrane and the geotextile, reducing longitudinal stress in the geosynthetic and preventing the materials from sliding down the slope.
3. Drainage and leachate collection
The seal retains the liquid, but it must also be actively collected. The drainage system consists of:
- River-washed gravel, size 16/32, thickness 0.50 m — over the entire surface of the cell bottom
- HDPE collection pipes on the main drainage lines, with gravity connection to the storage tank
- Installation shall be carried out only after the geosynthetic system has been fully accepted
4. The process route and related infrastructure
A storage cell requires access for heavy machinery (20–30-ton compactors) and transport vehicles.
- Load-bearing earthen formwork
- A foundation of ballast and crushed stone, compacted to the specified density
- Concrete cladding (resistant to heavy machinery loads)
- Gutters, walkways, and surface water drainage systems
Why the contractor's experience matters
A landfill is a facility with a lifespan of 30 to 50 years. A poorly welded geomembrane is not visible during the first five years of operation. It manifests as a crack in the water table after a decade, when repairs cost ten times more than proper installation from the start.
The Inoveco Experience:
- Over 300 environmental infrastructure projects completed in Romania
- Over 50 million square meters of geosynthetic materials installed over 30+ years
- Certifications: ARACO, ANIF, AFER, INSEMEX
- Certifications: ISO 9001:2015, ISO 14001:2015, ISO 45001:2018, ISO 27001:2018
- In-house crews for waterproofing and earthwork
Frequently Asked Questions (FAQ)
Q: What is a compliant storage cell?
A: A cell compliant with Government Decision 349/2005 and MMGA Order 757/2004 is lined with layered geosynthetic systems (GCL + HDPE + geotextile), equipped with a leachate collection system and a service road, with acceptance documented in phases.
Q: What is the thickness of the HDPE geomembrane used in a non-hazardous waste landfill?
A: For Cell 3 Ghizela: 2.0 mm. Textured on slopes, smooth on horizontal surfaces. This is the standard specification for non-hazardous waste.
Q: What is leachate, and how is it collected?
A: The liquid formed by rainwater seeping through the waste. It is collected via a drainage layer of washed gravel (16/32 grade, 0.50 m thick) using HDPE pipes and directed to a watertight storage tank.
Q: What is a bentonite geocomposite (GCL) and what is its purpose?
A: Geosynthetic material consisting of sodium bentonite sandwiched between two geotextiles. When in contact with water, it forms an impermeable mineral barrier (k ≤ 5×10⁻¹¹ m/s). At Cell 3 Ghizela: 5,000 g/m² GCL, the first synthetic layer of the waterproofing system.
Q: How is the quality of HDPE geomembrane welds checked?
A: Leak test (compressed air at 2–3 bar, in accordance with SR EN 13726) and/or spark tester (spark detection). No panels are covered prior to the acceptance of the welds.
Q: What permits are required to construct a landfill?
A: The contractor must hold an ARACO license for construction and, as applicable, ANIF, AFER, or INSEMEX licenses. Inoveco holds all of these licenses and also employs certified geomembrane welders.