In a side by side dig battle between hydro excavation and air excavation there is no contest, water will always win because it cuts faster and deeper than air ever could. However, when examining the factors of the specific job there are times where digging air might be a better or faster alternative. Let's take a look at a few of the factors that might determine when it would be best to use air or water for an excavation project.
Travel Time to Get Water for Hydro Excavation
At the start of the day (or end of the previous day) a hydro excavator unit, or jet vac, must be filled up with water. The refill process can take even longer if water is not available nearby, instead leaving an operator to drive far distances to fill up.
Larger hydro excavation units hold around 1300 gallons of water, whereas smaller units can have as little as 350 gallons. So even with the larger water tanks, you likely get between 3-5 hours of hydro excavation time before you run out of water. If you're lucky, your daily fill source is close by. If not, a lot of time can be spend traveling back and forth to get water for a hydro excavation job. This isn't a problem for us here at Cloud 9 Services, Inc. because we are located right next to a water source, so we are always ready to fulfill your hydro excavation needs.
Meanwhile, air excavation units rarely need water and almost always go the entire day (sometimes a week) without needing to be refilled. It is nice to have some onboard water when challenged with a difficult dig spot but is not always necessary. If your water source is nearby, this would be a non-factor issue. However, if you're driving a distance to reach a water source, it could point towards air excavation being a better alternative.
Travel Time to Debris Dump Site
Similar to the water source location, added travel to dump your debris tank can be a long and costly process for hydro excavation. Debris from the hydro excavation can rarely be used as backfill because of its slurry form and therefore must be dumped at a different location. In air excavation the debris is dry and can be used as backfill and dumped directly back into the same hole again. Again, if your dump location is close, this could be a non-issue. However, if your dump location is a time consuming distance away, air excavation may prove to be the better alternative.
Does This Project Require You to Backfill?
Understanding the scope of the project is an important factor to determining whether to dig with an air or water excavator. When do you get paid? Is it after the hole is dug and fenced off? Is it after the hole is dug, utilities exposed, repaired, documented and the hole returned to its original condition? As discussed previously, debris from air excavation can be immediately used for backfill, while hydro excavation may require time and costs to haul backfill material to the job site to backfill holes.
How large of an Area is being excavated?
Let us go back to one of the previous statements..."water will always cut faster and dig deeper." If you have a very large area (or several large areas) to dig, water will dig, water will drive faster results. Digging faster, as well as large debris tanks commonly found on hydro excavation units, will help negate or reduce some of the above previous hydro excavator pitfalls such as travel time to dump sites and to water sources when excavating larger areas.
Key Factors
Still not convinced on which service you should choose for your excavation project? Here are a few more key factors to consider.
Safety
Safety is always the number one priority on job sites. When a specific job requires digging near electrical wire, air excavation is recommended. This is because, unlike water, air is not a conductor. Regular air excavation allows workers to move soil away from underground electrical wires, or other more delicate utilities, without coming into direct contact with it.
Air excavation should also be utilized in areas where it's possible for water to cause a chemical reaction with the material.
Soil Conditions
Each site is different and soil condition is a big factor. Experience tells us that air excavation is better suited for loosely compacted soil or sand.
Hydro excavation is more versatile in this respect. It's effective at breaking up wet or rock soil, hard and compact dirt and clay. In colder climates or during the winter in northern states, hydro excavation is helpful because hot water can be employed to break up tough, frozen ground and permafrost.
Site Impact
Preserving the surroundings is more important on some job sites. When workers need to be careful not to disturb tree roots, utility lines or nearby buildings and infrastructures, air excavation might be the better choice.
On the other hand, hydro excavation is advised in certain conditions when blasting sand could damage something in the immediate area.
Bottom Line
At the end of the day, deciding which service is best depends on many factors. So do your research, choose carefully, and consider all the factors involved with the project before making a decision.
If you decide to go with hydro excavation, however, choose us here at Cloud 9 Services, Inc. and find out why we are the leading hydro excavation service provider in the Florida area! Contact us today to schedule your service, 407-481-2750, or get a free quote!