CEMP Air Quality for a Pre-Commencement Discharge in London

The Project

Our client, a mid-sized regional contractor, was about to break ground on a 120-unit residential scheme in a London borough. The borough had attached a pre-commencement air quality condition to the consent — standard practice for construction projects of this scale in London — requiring a Construction Environmental Management Plan (CEMP) including a Dust Management Plan (DMP) and a Non-Road Mobile Machinery (NRMM) compliance statement to be submitted and approved before any work could start on site.

The contractor had a fixed start-on-site date driven by trade procurement and material lead times. Ground-breaking was scheduled in just over six weeks. The clock was already running on the discharge submission.

The Challenge

The contractor had initially submitted an in-house CEMP document drawing on a generic corporate template. The borough returned it as inadequate, requesting much more detail on the IAQM dust risk classification, on the proximity-based receptor sensitivity assessment, and on demonstrating that all plant proposed for use on site would meet the relevant NRMM Stage V emission standards required by the Greater London NRMM Low Emission Zone.

A second failed submission would, on the borough's published response timescales, push the start-on-site date back by at least four weeks — with cascading consequences for trade sequencing, prelims costs and the overall project programme. The contractor needed a discharge submission that was right first time.

Our Approach

We carried out a site visit to confirm boundary conditions, identify nearby sensitive receptors and ground-truth the construction phasing assumptions in the contractor's programme. The closest sensitive receptor was a primary school 80m east of the site boundary, with residential properties immediately abutting the western boundary — both factors that materially raised the dust risk classification.

We then prepared the CEMP air quality chapter to the format set out in the IAQM 2024 guidance. The dust risk assessment concluded medium risk for demolition (small-volume strip-out only) and high risk for earthworks (driven by the proximity of the school and the volume of material to be moved during the dig). Construction was assessed as medium risk and trackout as low risk given the contractor's proposed wheel-wash arrangements. Each phase had its own bespoke mitigation matrix, broken down by activity, with named responsibilities and specified trigger levels for response.

For the NRMM compliance statement, we worked with the contractor's plant manager to develop a full plant inventory covering all items above the 37 kW threshold. Each item was tagged against its required emission standard (Stage V for 56–560 kW plant in the Greater London NRMM zone) and the registration strategy on the NRMM Register portal was set out clearly with named site responsibilities for ongoing record-keeping.

Crucially, we contacted the borough's Air Quality Officer at the outset and pre-agreed the format and level of detail expected. London boroughs vary in how they expect CEMPs to be presented — what one borough wants in a single document, another wants split across the CEMP, the DMP and the construction logistics plan. Pre-agreeing the format upfront removed an entire iteration cycle.

The Outcome

The CEMP was discharged at first submission. Construction commenced on programme. The contractor was sufficiently impressed with the document structure that they asked us to prepare CEMPs for two subsequent residential schemes in adjacent London boroughs over the following six months, using the same template adapted to each borough's specific requirements.