Landscape Rock and Caliche Debris in Mesa

Drive any street in east Mesa and try to count the lawns. In Red Mountain Ranch, Augusta Ranch, Superstition Springs or anywhere built from the 1990s on, you will run out of street long before you run out of fingers. Front and back yards here are rock, not grass. Decorative granite, decomposed granite, river rock, cobble and rip-rap, two or three inches deep over fabric, from the sidewalk to the block wall.

That is a sensible way to landscape somewhere that runs 105 to 118 degrees from May through September. It is also why, when a Mesa homeowner redoes the yard, the debris is among the heaviest material we haul. Rock is not really measured in cubic yards. It is measured in tons.

The call that goes sideways is always the same. Somebody has 900 square feet of faded granite coming out, pictures the pile, and asks for a 30 yard. What they need is a 10, hauled twice. This is the arithmetic behind that answer, and the second half of it is caliche.

The arithmetic nobody does first

Landscape rock in place runs roughly 1.3 to 1.5 tons per cubic yard — 2,600 to 3,000 pounds for every cubic yard you shovel up. Damp decomposed granite sits at the top of that range because the fines pack tight and hold water; screened three-quarter granite sits nearer the bottom. Neither end is forgiving.

Work it through. A 1,000 square foot front yard two inches deep is 1,000 multiplied by 0.167 feet, about 167 cubic feet, a little over 6 cubic yards — 8 to 9 tons. The same yard at three inches, which is what plenty of installers put down, is 250 cubic feet, 9.3 cubic yards, 12 to 14 tons. Add the back and side yards and a typical east Mesa lot holds 20 tons without anybody thinking of it as a heavy job.

Now put that in a box. The floor of a 10 yard roll-off is roughly eight by twelve feet, about 96 square feet. Four cubic yards of granite spread over it is a shade over a foot deep and already weighs five to six tons. A 10 yard filled to the rails with granite would be 13 to 15 tons, and no truck is hauling that legally. The box reaches its limit at about knee height. That is what rock weighs.

The pattern is the point. The answer to a rock job is almost never a bigger container. It is the same small container, more times. We would far rather bring a 10 and come back for it than drop a 30 that fills a foot deep and then sits in the driveway, loaded and unmovable, until somebody hand-shovels weight back out. It costs you less that way, not more, because you are paying for hauls that actually leave.

Caliche: the second half of the weight problem

Under the thin desert soil across the East Valley is a layer of caliche, and it deserves a proper explanation, because plenty of people who have lived here for years have only ever heard it called that hard stuff.

Caliche is a cemented hardpan of calcium carbonate. The little rain that falls here soaks a short distance in, dissolves lime out of the upper soil and then stops, because there is not enough water to carry it deeper. The lime is deposited at that depth, and over a few thousand years the soil grains there are glued into a solid layer. It starts a few inches to a couple of feet down and can be a crust or several feet thick.

What matters on site is how it behaves. Caliche does not shovel and it does not crumble. It breaks in slabs, more like unreinforced concrete than like dirt. A digging bar bounces off it and a trenching shovel bends. What gets through is a jackhammer, a breaker on a mini excavator or a rock auger, and what comes out is sharp-edged plate that stacks badly. Caliche is what turns a small dig into a weight job.

Where it turns up

• Pool demolition. The shell breaks out into gunite, the deck into concrete, and under both is caliche that has to be broken so the fill will drain. The biggest caliche producer here, and it needs a demolition permit from City of Mesa Development Services.
• Footings for a block wall, pergola or ramada — the trench hits hardpan on the way to bearing depth.
• Post holes for gates, shade sails and mailboxes. People budget an afternoon and lose the weekend.
• Trenching for irrigation, lighting or a new water line.
• Stump and tree removal, where the root ball comes up with plate wedged into it.
• Any landscape regrade dropping the level more than a few inches.

Why the trees go over in a microburst

Caliche also explains something every Mesa homeowner has seen. A mesquite or a palo verde grows a wide, shallow root plate rather than driving a taproot down, because the hardpan stops it, and drip irrigation keeps the water in the top few inches so the tree has no reason to search deeper. A mature canopy ends up on very little anchorage. That is why a monsoon microburst lays whole trees over sideways, the root plate lifting rock and fabric with it, and why the cleanup is wood, rock and caliche together — see yard waste removal.

Why the city cannot take any of this

This is the honest reason a roll-off is the route, and worth spelling out, because the City of Mesa runs a good solid waste utility and people reasonably assume it covers yard work.

• The green yard-waste barrel bans exactly this material. It takes grass, leaves, trimmings and small branches cut to 24-inch sections, and explicitly excludes rock and gravel, concrete, lumber, palm fronds, oleander trimmings, citrus fruit, cacti and metal. Read that list against a rock and caliche job and there is nothing left.
• Bulk collection will not take it either. The city's bulk pickup refuses construction and remodelling material outright and caps items at 60 pounds. One decorative boulder is over that.
• The Landfill Use Program is capped by weight. A Mesa utility customer may self-haul up to 2,000 pounds once per calendar month for $15, with a utility bill and photo ID. A genuinely useful programme, and also less than one heaped pickup bed of granite. One trip and the month is spent with 8 tons still on the ground.

Those routes are sized for household waste and green trimmings, and a rock yard is neither. Our page on what can go in a dumpster in Maricopa County covers the rest of the list, and Mesa dumpster permits covers a box that has to sit in the street.

The jobs this comes from

• A rock-to-turf or turf-to-rock conversion. Both directions make a load.
• Replacing faded or weed-choked granite. The commonest job of all: twenty years of fines, blown dust and Bermuda root has turned the top inch into soil.
• Pulling 1980s river rock and cobble to re-do in modern DG. Slow hand work.
• A pool fill-in — gunite, deck concrete, tile, coping and caliche, all dense. See demolition debris.
• Driveway or patio widening, mixing broken concrete with the rock and caliche under it.
• A block wall footing, where grouted CMU block comes out with the trench spoil.

Loading rock: flat and low, never mounded

Everything people learn from a garage cleanout is wrong for rock.

• Spread it flat across the whole floor. No pile at the door end. An even layer keeps the load balanced on the truck and the box square on the rails.
• Never mound it above the rails. Rule 310 requires at least three inches of freeboard between the load and the top of an open-bodied vehicle, plus a tarp. A heaped rock load cannot be tarped and cannot leave.
• Keep it a clean single-material load. Rock, concrete and caliche together are inert and go through the right gate. Add fabric, drip line, edging and two bags of household trash and the same load is mixed waste, bound somewhere else.
• Use a small box. Never put rock in a 30 or a 40. See the 10 yard and 15 yard, the full range on dumpster sizes, the same trade-off in the Mesa sizing guide, and inert loads under concrete and heavy debris.
• Say the word rock when you book. It changes which box we bring and where we set it. Protection boards go under every set, and on a July afternoon an asphalt drive is soft enough to take an impression.

A stripped yard is not just rock, either. Under it is landscape fabric torn into strips by the shovel, half-inch poly drip line with emitters, and steel or bender-board edging pinned with stakes. That material is a small fraction of the weight and the biggest single reason a clean inert load gets reclassified as mixed. Pull it out as its own pile before the rock goes in.

Before the shovel goes in: Arizona 811

Any rock removal that disturbs soil, and every caliche job, is a dig. Call 811 or file online with Arizona 811 — locals still say blue stake as a verb, but that is the organisation's name now. You need at least two full working days' notice before digging, not counting weekends or state holidays, and the marks stay valid 15 working days. What people actually hit is not the gas main. It is the shallow stuff: the irrigation main and drip laterals, a lighting run, a pool bond wire. Those are homeowner-installed and 811 does not locate them, so trace them from the valve box first.

Dust: the job class Rule 310 was written for

Breaking caliche and stripping rock is dry, dust-generating work in a metro area that is a serious PM10 nonattainment area. That is why the rules bite here, and the regulator is Maricopa County Air Quality, not the state.

• A dust control permit is required before disturbing 0.10 acre — 4,356 square feet — or more. Most single-family front yards fall under that; a whole-lot regrade does not. Under the threshold you still owe dust control, you simply do not need the permit.
• Loads leave covered, with at least three inches of freeboard and a tarp, every haul.
• Trackout control is required at 2 acres or more disturbed, or 100 cubic yards or more of bulk material hauled per day. A residential rock job is under that; a contractor running several boxes of spoil a day is not.
• When wind carries visible emissions across the property line, work stops and disturbed surfaces get stabilised.

Wet the material before loading. Damp rock is heavier, so keep the volume down to suit, but dry granite shovelled in a breeze is a plume for the whole street.

What the working day looks like

Rock removal is hand-shovel work. There is no machine for a fenced back yard with a three-foot gate, so it is a flat shovel, a muck rake, a wheelbarrow and somebody's back. From May through September that means starting before first light: on site at four thirty, working through sunrise, packed up by ten or eleven when the rock is unpleasant to touch. So October through April is the season for this work, backwards from most of the country. If the job is not urgent, book it for winter.

Pull the salvage before the box lands

Not everything in a rock yard is waste, and once it is in the container it is gone. Clean granite in good colour is reusable — screen it over expanded metal on a wheelbarrow, wash the fines off, and it goes back down in a side yard. Decorative boulders and flagstone are worth more in your own yard than at the bottom of a box. Sort the day before delivery, because once a box is on the drive the path of least resistance is to throw everything in, and every pound is a pound you paid to haul.

Tell us the square footage and the depth

Two numbers and we can size the job honestly on the phone: how many square feet of rock, and how deep. If caliche is coming out, say how much and whether it is broken or still in the ground. In HOA and master-planned communities, placement and duration are governed by your CC&Rs, so check with the association before delivery.

Sandstone Bros has run roll-offs out of the yard at 1913 N Rosemont, off McKellips in north-east Mesa, since 2013. Ruben answers the phone and Marco runs the yard. Expect us to talk you down to a smaller box on a rock job, and expect that to be the cheaper answer. Call (480) 757-9432 or use our contact page.