Utility Locates Before You Dig: The Field Procedure

The locate crew painted red down the front of the house, yellow to the meter, cleared the back yard and left. Your trencher went in at 22 inches along the side yard and stopped hard on a one-inch poly line at 16 inches — the water feed to the barn hydrant the homeowner's father put in twenty years ago.

Nobody marked it. Nobody was ever going to. That line has never existed in any utility's records, and the 811 call you made did exactly what it was supposed to do.

This is the gap that costs drainage crews real money. The public locate is free, fast and legally required, and it covers maybe half of what's actually buried in a typical residential yard. The other half is on you to find, and the time to find it is during the site visit, not with a crew standing around a cut line.

The 811 ticket covers less than most crews think

One call to 811 — or your state's online ticket portal — notifies every member utility with facilities in the area you described. Each of them either sends a locator to mark their lines or responds that they have nothing there. The service is free to you in every state.

What gets marked is the utility-owned facility, up to the point where ownership transfers to the property owner. That's the gas meter, the electric meter or weatherhead, the water meter or curb stop, the communications demarcation box on the wall. Past that point, it's private property and private responsibility, and the locator's obligation ends.

The practical effect: the gas service from the street to the meter gets marked. The gas run from the meter across the lawn to the pool heater does not. The water service to the meter pit gets marked. The line from the house to the barn does not. The sanitary sewer main in the street gets marked. The lateral running through the front yard usually does not, because in most jurisdictions the homeowner owns it.

File the ticket yourself rather than leaving it to a homeowner who says they'll handle it. You're the excavator. In nearly every state's one-call law, the legal duty to call and the liability for not calling sit with the person operating the machine.

The wait, the colours and the 18-inch rule

Standard notice is two to three full business days in most states, and the clock starts when the ticket is accepted, not when you dialled. Call Monday at 8 a.m. in a two-business-day state and you're legal Wednesday morning. If Monday is a holiday, shift everything a day. Emergency tickets exist for active gas leaks, sewage discharge and similar — they are not for a crew that showed up unprepared, and misusing them is how you lose standing with your local notification centre.

Waiting out the clock isn't the whole requirement. Most states also run a positive response system: every notified utility logs a response against your ticket number — marked, clear, or not complete. Check it before the machine moves. A silent member utility is not a cleared one.

Two things you can do that make the marks better. White-line the dig area first — paint or flags around the actual trench route — so the locator marks a corridor instead of the whole property, which gets you tighter, more useful marks. And photograph every mark the day it appears, with a fixed reference like a driveway edge or house corner in frame. Paint fades in a week of rain and mowers erase it in one pass.

Marks come as paint, flags, or offset marks with an arrow and a number — an offset of "3" means the line is three feet from the paint in the direction of the arrow. Read them before you assume the paint is over the pipe.

The tolerance zone is the buffer either side of the marked line where mechanical digging is prohibited. Eighteen inches from the outside edge of the facility is the most common figure, but states run 18, 24 and 30 inches, and some define it as the width of the facility plus a buffer. Look up your state's number once and write it on the shop whiteboard.

Inside that zone you hand dig, or you use vacuum excavation, until you've exposed the line and can see what you're dealing with. Locate marks carry horizontal accuracy only. Nothing in the paint tells you the depth, and a line installed at 30 inches in 1998 can be at 12 inches today after two regrades and a driveway replacement. Expose every crossing before you trench past it.

Marks expire, and so does the ticket

Tickets carry a working life — commonly 10 to 30 calendar days depending on the state, and some states count business days instead. When it lapses, you file an update or re-mark request rather than starting over, but you do have to file it.

This bites drainage contractors more than most trades because drainage work moves with the weather. You call the locate for a Tuesday start, the yard is soup for nine days, and by the time it's diggable the ticket is dead and the paint is gone. If you're already sequencing work around wet weeks, build ticket dates into the same calendar you use for crew commitments, and call the locate against the realistic start, not the optimistic one.

We don't have a field on a project for locate ticket numbers or expiry dates, and there's no automated reminder in ScapesHQ — custom fields and playbooks aren't built. A recurring calendar entry with the ticket number in the title does the job and costs nothing.

Re-mark before you trench if the paint is faded, the marks are inconsistent with your photos, or another trade has been on site since the locate. It's a phone call and another two days. That's cheaper than a strike every single time.

Private lines are the ones that actually get cut

In residential drainage, the strikes that cost you money are almost never the gas main. They're the things nobody thinks of as utilities. Here's the standing list to check on every yard:

• Irrigation mainline and laterals. Mainline is typically 10 to 18 inches, laterals often 6 to 10. Laterals run head to head, so you can usually sketch the network by walking the heads. The backflow preventer tells you where the system taps the water service.
• Invisible fence loop. Two to six inches deep, usually a continuous perimeter plus a run out to the transmitter in the garage. A trencher cuts it without the operator feeling anything.
• Low-voltage lighting. Direct-buried cable at four to eight inches, frequently just under mulch. Find the transformer on the wall and trace outward.
• Private gas. Runs past the meter to a pool heater, fire pit, generator, grill stub or detached shop. Usually poly, usually shallower than the utility's service, and the one on this list that can hurt somebody.
• Private water. Feeds to a barn, hydrant, pool autofill, outbuilding or hose bib island. Well lines from a well head to the house are pressurized and often deep.
• Private electric. Feeders to a detached garage, shop, well pump, gate opener, dock or pond pump. Direct burial cable at whatever depth the last guy felt like.
• Septic components. Tank, distribution box, and leach field laterals — and the field is the one thing you cannot trench through, repair and walk away from. Get the health department as-built before you price the job.
• Sewer lateral. From the house to the main. Ownership varies by jurisdiction; assume the homeowner's and assume it's unmarked.
• Existing drainage. Old downspout runs, a previous contractor's French drain, and buried sump discharge. If the sump line is already out in the yard, you want to know where it goes before you cross it — and where it terminates tells you a lot about the yard's history.

Some of these you can find yourself with a shovel and thirty minutes. Some need a private locator with a cable locator and a transmitter, and sometimes ground-penetrating radar.

Here's how the money works. Take a three-person crew at $38 to $45 per loaded hour in most markets — call it $40 for the arithmetic, which is $120 an hour. Add the mini ex at $20 to $35 an hour in ownership and fuel, call it $25. You're at $145 an hour standing still.

Now cut a one-inch irrigation lateral: half an hour finding the break, forty-five minutes round trip to the supply house, half an hour to splice, backfill and test. Two hours at $145 is $290, plus roughly $25 in fittings. Call it $315 and a crew that's now behind on the trench.

A private locate on a typical residential lot runs $150 to $400 per visit in most markets, more for large properties or where radar is needed. One avoided irrigation cut roughly pays for it. One avoided private gas line pays for ten, and doesn't put anybody in the hospital.

The rule that survives contact with the real world: pay for a private locate any time the trench crosses between the house and a detached structure, pool, well, or septic field. Those are the four situations where something substantial is almost certainly buried in the path.

The pre-dig walk that finds them

Do this on the estimate visit, not on dig day, because what you find changes the price. Fifteen minutes with a clipboard:

1. Walk the trench route end to end and mark it with white paint or flags. You're now looking at a corridor, not a yard.
2. Find the meters. Gas meter, water meter or curb stop, electric service, and the comms box. Anything running away from those toward an outbuilding is private.
3. Find the irrigation controller and count the zones. Eight zones means eight valve circuits and a lot of lateral in the ground. Open the valve boxes and see which direction the pipe leaves.
4. Look for the transformer on the wall near an outdoor outlet — that's lighting. Look for a small wall-mounted box in the garage with an antenna-ish wire — that's the dog fence.
5. Inventory anything in the yard that has power or water: pond pump, hot tub, gate, coop, shop, pool equipment pad, outdoor kitchen. Each one has a line coming to it from somewhere.
6. Probe the crossings. A tile probe or a shovel at every point where the trench route passes something suspicious, before anyone quotes a start date.

Then ask the homeowner, directly, and write the answers down:

• Do you have irrigation? Who installed it, and is there a drawing?
• Is there a dog fence — now, or from a previous owner or a previous dog?
• Is anything out in the yard running on gas, water or power?
• Are you on septic or sewer? If septic, when was it last pumped and where did they open it?
• Has anyone trenched here before — pool, fence, cable, another drainage contractor?
• Is there a propane tank, above or below ground?
• Have your sump or downspouts ever been piped out into the yard?

"I don't know" is a real answer and a useful one. It tells you the yard needs a private locate rather than a conversation. It's also one more reason a diagnostic visit is worth charging something for — this walk is skilled work, and it's how you avoid pricing a job you can't actually dig.

Who pays, and what to write into the scope before anyone signs

Three situations, three different answers, and they're worth knowing cold before you're standing over a cut line arguing about it.

You hit a marked public line. If you dug mechanically inside the tolerance zone, or dug on an expired ticket, or never called at all, you own the repair and quite possibly a statutory fine on top. This is the scenario with the largest downside and the simplest prevention.

You hit a mismarked or unmarked public line. If the locator put the paint in the wrong place and you can show you dug where the marks said it was safe, the liability generally shifts to the utility or its locating contractor. Whether you can show that depends entirely on the photographs you took on day one. This is the whole reason for the photos.

You hit an unmarked private line. In most states, locating private facilities is the property owner's responsibility, and the one-call law simply doesn't apply. In practice, what happens is decided by what's in your contract and how you behave in the next ten minutes. No paperwork means an argument, and an argument on day one poisons the rest of the job.

So write it down before anyone signs. Something close to this, in your own words:

Public utilities will be located through the state one-call system at no cost to the owner. Private underground facilities — irrigation, landscape lighting, pet containment, septic components, and private gas, water, electric or communication lines serving outbuildings, pools or other structures — are not covered by the public locate. Owner agrees to identify all known private lines in writing before work begins. Contractor will hand dig at all identified crossings. Repair of damage to unmarked or misidentified private lines will be billed at time and materials. Contractor will notify owner before performing any such repair.

That clause does two jobs. It sets the financial boundary, and more usefully it prompts the homeowner to actually go looking in the kitchen drawer for the irrigation drawing. Half the private lines you find get found because a clause like this made someone think about it.

When you do cut something, the procedure is the same as every other buried surprise: stop, photograph it in place, call the homeowner out to look at it, and price the repair off your own numbers before you fix it. That's the same discipline as handling rock or an unmarked line as a change order — the customer who watches you find it and hears the number before you swing a shovel almost never fights the bill.

One more place this belongs: your warranty. If a cut lateral gets spliced and the irrigation system leaks eight months later, you want to have already said in writing what's covered and what isn't. Name private-line repairs explicitly among the exclusions you list by name rather than leaving it to interpretation.

Put the private-utility clause into your standard proposal template once and it rides along on every job after that. In ScapesHQ that's a template edit, and the signed copy with the homeowner's acceptance sits on the record with the rest of the send history — which is exactly where you want it eight months later when somebody's memory has gone soft.

FAQ

How long do I have to wait after calling 811 before I can dig?

Most states require two to three full business days, and the clock starts when the ticket is accepted rather than when you called. Holidays and weekends push it further out. Beyond the waiting period, check the positive response system so you know every notified utility has either marked its lines or responded clear.

Does 811 mark irrigation lines and invisible fence?

No. The public locate covers utility-owned facilities up to the meter or demarcation point. Irrigation, pet fence, low-voltage lighting, septic components and any gas, water or electric run past the meter to a shop, pool or barn are private and get marked only if the owner hires a private locator.

How long is an 811 ticket good for?

Commonly 10 to 30 days depending on your state, and some states count business days rather than calendar days. Look up your number once and treat it as a hard date. If weather pushes the start past the expiry, file an update or re-mark request rather than digging on faded paint.

Can I use a machine inside the tolerance zone if I go slowly?

No. Inside the tolerance zone — most often 18 inches either side of the marked facility, though 24 and 30 inches apply in some states — you hand dig or vacuum excavate until the line is exposed. Marks give horizontal position only, so a line installed at 30 inches can sit at 12 inches today after regrading.

Who pays when a crew cuts an unmarked private line?

In most states, locating private facilities is the property owner's responsibility and the one-call law doesn't cover it. What actually happens depends on your contract, so put a private-utility clause in the proposal that names the categories, asks the owner to identify what they know about, and states that repairs to unmarked private lines are billed at time and materials.

The short version

Call 811 yourself, white-line the route, wait the full notice period, check positive response, and photograph every mark before the machine moves — then hand dig the tolerance zone at every crossing. The strikes that cost residential drainage crews money are private: irrigation, dog fence, lighting, septic, and gas or water runs to a pool or shop, none of which the public locate touches. Find them on the estimate visit with a fifteen-minute walk and seven direct questions, price a private locate any time the trench crosses to a detached structure, pool, well or leach field, and put a private-utility clause in the proposal so the money question is settled before anyone signs.

Book a walkthrough and we'll look at where a private-utility clause would sit in the proposals you're already sending.