Environmental monitoring

While traditional methods like fixed-volume purging, bailers, or submersible high-flow pumps can remove stagnant water in wells, they often introduce significant scientific and practical issues. Low-flow purging and sampling extract groundwater at rates under 500 ml/min, Aligning with natural groundwater flow. Our approach:

• Minimises drawdown: reduces mixing of stagnant water in the well.
• Preserves sample integrity: maintains more accurate water chemistry for dependable data.
• Lowers disposal costs: generates significantly less purge water for handling and off-site treatment.

We provide comprehensive ground gas and vapour investigations aligned with CIRIA C665, BS8576, and NHBC recommendations. By developing a preliminary conceptual model during the phase I study or early in the ground gas risk assessment process, we identify potential sources, whether landfill, peat, coal mine, or fill-derived strata, and design a site-specific monitoring regime accordingly.

Advanced monitoring equipment

• MiniRAE 3000 PID: fully calibrated for VOC monitoring, including on-site screening of soils and waters via headspace testing, as well as standpipe installations.
• Geotechnical instruments GA5000: measures oxygen, carbon monoxide, carbon dioxide, hydrogen sulphide, and methane, in addition to flow via an internal flow pod.

By detecting lateral movements within structures or strata, we can advise on remedial measures if signs of instability are identified, helping you prevent costly failures and maintain site safety. We install standpipe casings in boreholes and use a specialised inclinometer probe to track any shifts in the earth. This high-precision method captures detailed data on how soil or structural elements move over time, making it ideal for assessing potential hazards in unstable slopes, dam walls, roadway embankments, or deep excavations.

Data processing & reporting

• Accurate graphs: our advanced software generates incremental lateral movement graphs against initial base readings.
• Comprehensive analysis: we also provide cumulative movement and absolute position graphs, ensuring a clear understanding of the site’s stability profile.

We specialise in investigating hydrocarbon-contaminated sites, particularly those with NAPLs (non-aqueous phase liquids) derived from heating oils. Our approach thoroughly identifies contamination sources and accurately measures the extent of pollution, helping you make informed decisions about site remediation and future development.

Our monitoring process

1. Exploratory holes

• Drilled to confirm or rule out suspected contamination.
• Standpipes installed for in-situ groundwater sampling and monitoring.

2. Oil/water interface probe

• Determines the thickness of NAPLs within the standpipe.
• Utilises a precision float to detect the NAPL’s surface and a conductive probe to identify the groundwater interface.

From pile drilling and heavy transport to construction, demolition, and trenchless techniques (e.g., directional drilling), our monitoring solutions keep you fully informed and in control. We deploy Omnidots Swarm Vibration Monitors, positioning them at agreed locations on your site. These monitors continuously track tri-axial PPV & VDV in line with BS5228-2, BS7385-2, and BS6472-1, transmitting data via 4G or Wi-Fi for GPS and time-synchronised, offsite remote observation.

Real-time alerts & reporting

• Amber and red alarms: if set limits are exceeded, the system automatically alerts our team and your designated site personnel.
• Immediate action: site managers can pause activities to prevent damage when alarm thresholds are breached.
• Weekly reports: we deliver ongoing updates detailing peak particle velocity (PPV) and frequency (Hz) to ensure you have a clear understanding of on-site vibration levels.

During redevelopment or remediation, surplus waste soils are often generated. As the waste producer, you’re legally required to classify these soils before they leave your site. At A F Howland Associates, we ensure you meet this obligation, while potentially reducing landfill taxes and lowering overall disposal costs.

Hazardous or non-hazardous?

• Accurate classification: we determine whether waste soil is hazardous or non-hazardous according to European Waste Catalogue (EWC) 2002 and EC Regulation 1272/2008.
• Cost savings: proper classification can significantly lower landfill taxes, especially given the limited number of hazardous landfill sites in the UK.