Permit tonnage limit: how much waste a site may take

A permit tonnage limit is the maximum weight of waste an environmental permit allows a site to accept, store and handle, stated in the permit document the Environment Agency issued for that site. Most permits for a skip yard or transfer station carry two numbers that matter day to day: a throughput figure, the tonnage the site may take over a year, and a storage figure, the tonnage that may sit on the ground at any one time.

There is no national number you can look up and apply to your yard. The figures follow the activities the site applied for, the waste types named on the permit and any conditions the area office attached, so two yards a mile apart can hold very different ceilings. A site operating under a waste exemption rather than a permit has its ceiling set by the exemption instead, and exemption ceilings are the tighter ones. The practical rule is the same either way: the authority is the paper you were issued, so read the limits off it rather than off anybody's summary.

What the figure gets measured against

Your tonnage is nothing more than the sum of the loads you wrote down. Every weighbridge ticket and every waste transfer note is a line in that sum, which means the quality of the total is the quality of the note keeping behind it. A yard that scribbles weights on a pad and adds them up at the end of the quarter is reconstructing the figure after the fact, and reconstructions tend to be generous in whichever direction nobody checked. A yard that records each load as it tips already has the running total.

Say a transfer station's permit allows 25,000 tonnes a year of non-hazardous waste, and no more than 500 tonnes on site at any one time. Those two conditions fail in completely different ways.

The annual figure fails slowly. By the end of September the yard has taken 20,000 tonnes, which leaves 5,000 for the last quarter. Nobody notices until the muck away work in November is already booked, and by then the choice is between turning loads away and going over.

The storage figure fails quickly. It can be breached on a wet Friday when the outlets are shut, two hauliers both tip, and nothing has left the yard since Wednesday. It is the number a visiting officer can see for themselves standing in the bay, so it is the number worth knowing before they arrive.

Both cases are easier to manage with a tonnage total that is current rather than quarterly, broken down by the waste types your permit names, because a limit that applies to one waste stream cannot be checked against a single mixed figure.

• Environmental permit. The authorisation that lets a site carry out a waste operation at a named address. The tonnage limit is one condition inside it, alongside the permitted waste types and the site's operating rules.
• Waste exemption. A registration for lower risk, smaller scale waste activity, with its own ceilings instead of a permit's. Yards that outgrow an exemption usually meet their first tonnage limit on the way into a permit.
• Standard rules and bespoke permits. Standard rules permits come with set conditions, including the tonnage ceiling for that class of activity. A bespoke permit carries figures negotiated for that specific site.
• Throughput and storage. Throughput is what came in over the period. Storage is what is sitting there now. A permit can cap either, or both.
• EWC code. The six digit List of Waste code that identifies what a load actually is. Where a permit limits a waste type, the code is how you tell which loads count.
• Waste transfer note. The duty of care record for each movement, and the line item behind every tonne in your total.
• Weighbridge ticket. The weight itself, taken at the gate. There is a separate page here on what belongs on one and how it reaches the transfer note.
• Quarterly return. The periodic submission to the Environment Agency summarising what the site handled, built from the same notes as your tonnage total.

There are fuller pages on this site covering the weighbridge ticket and the waste transfer station themselves, and one on getting the weight from the ticket onto the note without typing it twice.