Concrete Disposal in Rock County: A Clean Fill Guide

Concrete disposal in Rock County is governed by two local facts rather than by general industry practice, and if you only take one thing from this page, take the second one — it changes the answer for four months of the year.

The two rules that govern masonry here

First: the Rock County and City of Janesville Sanitary Landfill on Black Bridge Road does not accept concrete. It is banned outright, including reinforced concrete, and sits on the prohibited list alongside yard waste.

Second: clean masonry routes instead to the Clean Fill Facility just west of the landfill — and that facility closes from the beginning of December until the end of March.

Together those mean a concrete job in this county is never simply "put it in a container." It is always a question of which container and, for a third of the year, of whether the job should happen now at all.

Why concrete is banned from the landfill

It is not a hazard question. Concrete, brick, block and clean stone are inert — they do not leach, decompose or generate gas.

The reason is that landfill space is a finite and expensive resource, and burying inert material that can be crushed and reused as aggregate wastes it. Wisconsin's whole regulatory posture pushes in this direction: the state's recycling statutes ban a long list of materials from landfill, and the state applies disposal surcharges specifically to make landfilling less attractive than recovery.

So concrete gets diverted to a facility set up to handle it as a recoverable material. That is better environmentally and, when the load is genuinely clean, cheaper for you than mixed disposal would be.

The winter closure

This is the part almost nobody plans for.

The Clean Fill Facility, along with the neighbouring compost site, does not keep regular hours in winter. Both close from the beginning of December until the end of March. The exact dates flex with the weather — they may close later in December or reopen earlier in March if conditions allow — but you cannot plan a January masonry job on the assumption the gate will be open.

What that means in practice:

If your masonry job can wait until April, waiting is usually the cheaper decision. We will tell you that even though it means a booking we do not take this month. A patio tear-out is rarely urgent, and moving it three months can meaningfully change what disposal costs.

If it cannot wait, ring and we will work out the winter routing before you commit. There are options, they simply cost differently, and you should know the number in advance rather than after.

There is an irony worth noting. Winter is actually the easiest time of year to get a truck onto a soft rural driveway, because frozen ground carries weight that the same drive will not carry in April. So for access, winter is good; for concrete specifically, it is the awkward season.

What counts as clean fill

The distinction matters because one contaminated item reclassifies an entire load.

Clean fill: poured concrete, concrete block, brick, unpainted stone and masonry, asphalt, clean soil and gravel.

Not clean fill: gypsum board, plaster, painted or treated timber, anything with sealers or coatings, metal, tile with adhesive backing, and general construction waste. Those go in a general container to the sanitary landfill instead.

Rebar cast inside concrete is normally acceptable. Mesh or bar protruding from broken slabs is not, because it fouls processing equipment. Cut it back flush where you can.

The practical rule on site: if you are demolishing a foundation and the timber sill plate is still attached, get it off before it goes in. That five minutes is the difference between a clean-fill rate and a mixed-debris rate on the whole container.

Why the container is small

Heavy material goes in a 10 yard, filled to a level load and no higher. This surprises people and it is not caution.

Concrete runs to roughly two tons per cubic yard. A 10 yard container filled level with it is already at the legal road weight for the truck carrying it. A 20 or 30 yard filled with masonry could not legally be moved — it would sit on your property as an extremely expensive ornament until somebody removed material by hand.

For a larger demolition we run multiple 10 yard containers or stage them across the job. More deliveries, and the only way it can be done.

Stone, soil and excavation

Three related materials that behave the same way.

Stone. Old foundations, retaining walls and stone patios all qualify as clean fill unmixed. The tonnage in even a modest wall is usually far more than the owner expects.

Soil. Heavier than people believe, and wet soil heavier again. A 10 yard of saturated ground hits road weight well before it is level. If the soil is of unknown origin or potentially contaminated it needs testing before disposal, and at the Rock County landfill contaminated soil is a special waste requiring prior approval.

Excavation spoil. The most commonly underestimated material we handle. If you are excavating, tell us the cubic yardage and we will work out the number of containers rather than guessing, because the answer is routinely higher than the original estimate.

Planning a masonry job properly

Four things, in order.

Check the calendar first. December through March changes the routing. April through November is straightforward.

Estimate the volume honestly. Measure the slab or wall and work out the cubic yardage rather than eyeballing it. Multiply by roughly two tons per cubic yard and you will see immediately why the containers are small.

Separate before you load, not after. Timber, rebar ends, sealed or painted material and gypsum all need to be out of the masonry stream.

Tell us the whole job. If there is a general demolition phase alongside the concrete, we will schedule both containers together rather than treating them as two separate bookings, which is cheaper and less disruptive.