Measure the casing before you order anything
The limit on this job is not how much dirt you want to move. It is how much exposed casing you can afford to give up. Every inch of fill you place is an inch subtracted from the pipe sticking out of the ground, and that exposed height is the thing a well inspector measures.
So the first tool you need is a tape measure, not a shovel. Measure from the top of the casing, or the top of the well cap flange if that is what your local rule references, straight down to the existing dirt at the base. Do it on all four sides. Rural ground is rarely level, and the low side is the number that matters, because that is where your finished grade will be highest relative to the pipe.
Wisconsin DNR is one of the few state regulators that publishes plain numbers on this. Its well casing height guidance requires a 12 inch minimum casing height above finished grade for outdoor wells installed on or after February 1, 1991, 8 inches for older wells, and 24 inches above floodplain elevation for wells sitting in a floodplain. Rules vary from state to state, so treat those as the shape of the requirement rather than your personal number. Confirm with your own state or county well program before you order material.
Pay attention to the word finished. The height is measured from grade after your project is done, not before. The same guidance specifically warns that raising or lowering grade near a wellhead, including things like building a raised bed against it, can leave you with a casing height that no longer complies.
A simple worked example. Say your casing stands 18 inches out of the ground and your requirement is a 12 inch minimum. That leaves you 6 inches of budget. Six inches is one lift of compacted fill plus a thin topsoil cap, not a truckload dumped and raked out by eye. Knowing that number before the delivery shows up is the difference between a clean job and a pile of dirt you cannot legally place.
If the measurement says you have less clearance than you need, do not start negotiating with yourself about it. Skip ahead to the section on casing extensions.
Why water is pooling at the base in the first place
Two very different problems look identical from ten feet away. Surface water collecting in a low spot is a grading problem, and fill dirt with proper slope is the right answer. Water coming up at the casing itself, or seeping from the pipe, can be a failed seal or a casing problem, and no amount of dirt will fix that.
Here is a rough field test. If the puddle only appears after heavy rain, dries out over a few days, and the surrounding yard visibly drains toward that spot, you are looking at a grading issue. That is a dirt job.
If there is water at the base during dry weather, or the ground around the casing stays saturated with no rain to explain it, stop and call a licensed well contractor before you move a single wheelbarrow. Burying a problem you have not diagnosed is the expensive version of this project, because you will be digging the same dirt back out later with a service truck parked in your yard.
Causes worth recognizing when you walk the site:
- Settled backfill from the original drilling. The soil around a new well is disturbed and it keeps compacting for years, which slowly turns the area into a dish.
- Roof runoff or a driveway shedding toward the well. A barn or shed with no gutters can dump a surprising volume in one storm.
- An old well pit or casing pit that collects water instead of draining it.
- Mower or vehicle damage that has pushed and rutted soil down around the pipe over the years.
Why standing water at the casing is worth taking seriously at all. The outside of the casing is the easiest downward path surface water can find, and surface water carries whatever is sitting on your lawn with it. That is also why it is worth keeping fertilizer and herbicide application well away from the casing, especially right after you seed a freshly regraded area and are tempted to hit it with a starter product.
How much fill dirt around a well head, in actual cubic yards
Scope this as a pad, not as a yard wide project. You are building a low mound centered on the casing that extends several feet in every direction and then feathers out into existing grade. The feathering matters. A pad with an abrupt edge is just a small dam, and you will trade a puddle at the pipe for a puddle at the perimeter.
Working out the pad area
For a sense of how wide is wide enough at the surface, UGA Cooperative Extension's wellhead protection guidance describes watertight surface curbing as a concrete slab extending at least 2 feet in all directions from the casing and sloping away from it. A dirt pad should be wider than that, not narrower. Concrete can shed water over a short run because it is hard and smooth. Dirt and grass need a longer run to do the same job.
In practice, most acreage owners end up somewhere between a 12 foot and a 20 foot diameter pad. Pick your diameter by looking at where the ground currently falls away on its own. You want your new slope to tie into existing grade that already drains, not to stop short in the middle of a flat spot.
Doing the math with our coverage numbers
Here are the specs for our fill dirt, so you can run the arithmetic yourself. Density is 1.3 tons per cubic yard. Typical install depth is 6 to 12 inches. One cubic yard covers about 54 square feet at 6 inches deep.
Worked example one. A 12 foot diameter circle around the casing is roughly 113 square feet. At an average added depth of 6 inches, divide 113 by 54 and you get about 2 cubic yards. At an average of 9 inches, the coverage per yard drops to roughly 36 square feet, so 113 divided by 36 is closer to 3 cubic yards. In tons, 3 cubic yards times 1.3 tons per cubic yard is about 3.9 tons.
Worked example two. A 20 foot diameter circle is about 314 square feet. At an average of 6 inches, 314 divided by 54 is roughly 6 cubic yards, or about 7.8 tons at 1.3 tons per cubic yard.
Now the reality check that trips people up. A crowned pad is deepest at the casing and tapers to nothing at the outer edge, so your average depth is well under your maximum depth. If you want 9 inches of build at the pipe and zero at the edge, your average across the pad is far less than 9 inches. Estimating on maximum depth is exactly how people end up with a mound of leftover dirt they cannot legally place at the well.
Add a little for compaction. Fill placed in lifts and tamped loses volume as the air comes out of it, so ordering slightly over the paper number is normal and sensible. Running out halfway through a lift is worse than having a wheelbarrow or two left over for a low spot elsewhere on the property.
One more ordering note. Buy fill dirt for the structural part of this job, not topsoil. Topsoil is a growing medium. It is soft, organic, and it settles, which is the opposite of what you want holding a shape around a well casing. If you are working from a total square footage rather than a circle, our material calculator will convert area and depth into yards for you.
Why clay heavy fill beats loose sand at the wellhead
The entire purpose of this pad is to move water sideways, away from the pipe. A tight, clay heavy fill dirt does that well. Loose sand does the exact opposite. It lets water travel straight down through it and then collects that water against the outside of the casing, which is the one place you were trying to keep it away from.
Fill dirt is subsoil from local excavation, screened of debris. That is exactly the character you want here. It is dense, low in organic matter, and it will not rot down and resettle into a fresh dish two summers from now.
There is a useful parallel in how wells are built. Standard well construction guidance calls for the annular space around the casing to be grouted from the ground surface down, with sand or gravel fill used only below that grout section. Permeable material belongs deep, sealing material belongs at the top. The same logic applies to whatever you place on the surface.
So do not ring the casing in loose gravel or sand on the theory that it will drain. It will drain, straight down the outside of the pipe. If you want stone at the wellhead as a mow strip or for splash protection, that is fine, but put it on top of a properly sloped and compacted dirt pad rather than instead of one. The dirt does the shedding. The stone just keeps the string trimmer off the casing.
Organic material is the wrong call here for the same reason. Mulch, compost, and screened topsoil all break down and lose height. That is a feature in a planting bed and a problem at a wellhead, because it quietly changes your finished grade over a few seasons without anyone noticing until there is water standing again.
Building the slope: lifts, compaction, and fall per foot
Start by stripping the sod and any soft organic layer off the pad area. Fill placed over living grass and mush settles unevenly, and uneven settlement is how a fresh regrade turns into a new low spot.
Place the fill dirt in 6 to 8 inch lifts and compact each lift before adding the next one. This is the single most important instruction in the whole article. Skipping it is the most common reason a regrade goes back to being a puddle within two years, because the ground keeps settling long after you have seeded it and moved on. A plate compactor rental for an afternoon beats stomping it with the back of a shovel, and on a pad this size you can be done in a couple of hours.
Be deliberate about the first foot around the pipe. You do not want loose fill washing down the outside of the casing. Tamp firmly right at the pipe and hand work that inner ring rather than driving equipment against it.
Slope target. Standard practice for shedding surface water away from a structure is roughly 6 inches of fall over the first 10 feet, which is about 5 percent. At a wellhead, a bit steeper near the casing and gentler as you feather out works well. The requirement is that the whole run falls away in every direction and does not dead end into a new low spot somewhere on the far side.
Check the result rather than trusting your eye. A level sitting on a straight board, or a string line with a tape measuring down from it, will tell you the truth. Eyeballing slope on uneven acreage is unreliable, especially when the surrounding ground is already tilted.
Think about where the water goes next before you build, not after. Walk downhill from the pad. If you redirect a puddle from the casing to a spot ten feet away that also holds water, you have not solved anything, you have just moved the mosquitoes.
Cap with topsoil and seed only after the structural fill is at final grade and compacted. Remember that the topsoil cap counts toward finished grade too, so include those inches in your casing height math from the start. If you budgeted 6 inches of clearance and then add 2 inches of topsoil on top of 6 inches of fill, you are over.
Finally, measure the casing height again after the first few good rains. Freshly placed fill settles even when it has been compacted well, and it is much easier to add an inch than to dig one back out from around a pipe.
When you cannot add fill: casing extensions and other options
If the math says you need more fill than your casing clearance allows, the fix is to raise the well, not to bury it. A licensed well contractor can add a casing extension so the pipe meets the required height above your new finished grade. That turns an impossible grading job into a straightforward one, and it is a routine piece of work for anyone who drills wells.
Burying a casing below the required height is a code violation in most jurisdictions, and the practical consequence is worse than the paperwork. You remove the physical barrier that keeps surface water out of your drinking water. You also make the well harder to service and much easier to clip with a mower deck, since nobody can see where it is.
A few situations that need a professional opinion rather than a plan you make on a Saturday morning:
- Pitless adapter wells. The adapter is a below grade connection point in the casing. Changing grade around it is a conversation for a well contractor, not a DIY decision made with a tape measure.
- Old well pits. Backfilling a pit to eliminate a water collecting hole usually involves bringing the casing up above grade first, and this work is often regulated. Get guidance before you fill one in.
- Any well where you are not certain of the construction date. The required height can differ for older wells, and guessing in the wrong direction is expensive.
A concrete apron or curbing is an option some owners choose on top of the grading work. The UGA guidance describes watertight surface curbing as a slab at least 4 inches thick extending at least 2 feet in all directions from the casing and sloping away from it. A dirt regrade and a concrete apron are not competing choices. The dirt sets the shape and the elevation, and the concrete finishes the few feet closest to the pipe.
Call your state or county well program before the project rather than after. They will tell you the casing height number that applies to your well and whether your plan needs a permit. That phone call costs nothing and it is the only way to be certain the number you are building to is the right one.
How We Started
We started Mulch Mound because we got tired of the hassle that came with buying landscaping materials. The options were either loading bags into your car at a garden center or calling around to local suppliers, trying to figure out pricing, minimums, and delivery schedules. Neither option felt convenient or transparent.
Three of us – Alec, Mo, and Tyler – decided there had to be a better way. Alec and Tyler got their start back in 2013 running a landscaping business during college, moving mulch and mowing lawns to pay tuition. That experience taught them how frustrating it was to source materials, and years later, that frustration turned into Mulch Mound.
We focus on making it simple to get mulch, stone, and soil delivered directly to your home. Order online, pick your delivery date, and we handle the rest. No loading bags. No calling multiple suppliers. No wondering if you bought enough or paid a fair price.
We work with quality local suppliers in the areas we serve and aim to be straightforward about what we offer and what it costs. Landscaping is hard work. Buying the materials for it shouldn't be.
Frequently asked questions
Can I add dirt around my well casing to fix a low spot?
Yes, within the clearance your casing gives you. The practical test is whether you can place all of your fill, including the topsoil cap, and still measure the required exposed height at the lowest point on the finished pad. Not the average point, the lowest one.
If the answer is no by even an inch, stop and price a casing extension instead of talking yourself into it. An inch of shortfall is still a failed measurement when someone checks it during a well test.
Why is water pooling around my well head after heavy rain?
On acreage it is frequently not the well's fault at all. Trace the water uphill and look for something that changed. A new gravel drive, a ditch that got filled during a fence project, a barn roof running without gutters, or a field graded years ago by a previous owner can all send water somewhere it did not used to go.
Fix the source where you can. If you gutter the outbuilding or cut a shallow swale higher up, the pad you build at the wellhead will handle a much smaller volume and last considerably longer.
Do I need a concrete apron or slab around the wellhead?
Not always, and it depends on your state's rules. A well built dirt pad with real compaction and real slope handles ordinary surface water without any concrete at all.
Concrete earns its keep in two situations. One is where there is regular foot or equipment traffic right at the casing, such as a wellhead near a barn door or a turnaround. The other is where the soil simply will not hold a shape, which is common on sandy ground where every rain rounds off the crown you built.
What kind of fill should I use to backfill around a well?
Dense, low organic subsoil, placed in 6 to 8 inch lifts and compacted as you go. Screened fill dirt fits that description and sits in a low price band compared with garden soils and blended mixes, which is a nice side benefit when you need a few yards.
Save topsoil for a thin cap at the very end if you want grass growing on the pad. Do not use it as the body of the fill, and do not use compost or aged manure anywhere in the structure.
What happens if the well casing ends up buried below grade?
You lose the separation between surface water and your water supply, which is the whole reason the height requirement exists. You also likely fall out of compliance with your state or county rules.
The practical sting usually arrives later. A buried casing becomes an inspection problem during a well test or a home sale, and it is genuinely hard to locate when the pump needs service and there is a truck waiting in the driveway.