Ask Astor

Ask Astor

Our Ask Astor series is a Q & A column which focuses on providing answers to your most frequently asked questions about the landfill. Astor Lawson, our District Manager at Bethlehem Landfill, is an industry expert with more than 16 years successfully managing landfills.

QUESTION: How do landfills prevent groundwater contamination?

ANSWER:

At Bethlehem Landfill, we are committed to protecting the groundwater from contamination. We use a range of methods to ensure environmental safety and public health in our community. Some of the actions Bethlehem Landfill takes to protect groundwater are as follows:

1. Engineered Liner Systems
   1. Primary Liners: High-density polyethylene (HDPE) liners form an impermeable barrier at the base, preventing leachate from penetrating the soil.
   2. Secondary Liners: A secondary high-density polyethylene (HDPE) liner forms an additional impermeable barrier at the base.
2. Leachate Collection and Management
   1. Drainage Layers: Gravel and perforated pipes collect leachate efficiently, directing it to collection systems.
   2. Treatment Facilities: Collected leachate is conveyed to a PFAS pretreatment facility and then directed to a POTW facility where contaminants are removed before safe discharge or reuse.
3. Groundwater Monitoring
   1. Monitoring Wells: Strategically placed wells around the landfill perimeter provide continuous sampling and analysis of groundwater quality.
   2. Regular Testing: Routine testing ensures early detection of potential contamination, allowing for prompt corrective actions.
4. Protective Soil Layers
   1. Compacted Soil: Compacted clay layers beneath the liners reduce permeability, further preventing leachate migration.
   2. Intermediate Covers: Daily operational covers minimize exposure to precipitation, reducing the generation of leachate.
5. Final Capping Systems
   1. Sealing Caps: Upon reaching capacity, landfills are capped with a multi-layer system including soil, synthetic materials, and geomembranes to prevent water infiltration.
   2. Vegetative Layer: A vegetative cover stabilizes the cap, reduces erosion, and enhances long-term integrity.
6. Operational Best Practices
   1. Waste Compaction: Proper compaction techniques reduce voids and limit leachate formation.
   2. Daily Cover Application: Applying a daily cover of soil or alternative materials minimizes rainwater contact with waste.

By adhering to these rigorous standards, landfills effectively protect groundwater resources, ensuring sustainable and responsible waste management practices.

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