9 Reliable Ways To Transport A Portable Waste Tank Externally For Boondocking

Boondocking in remote locations offers unparalleled freedom, but it also presents the inevitable challenge of managing wastewater once your holding tanks run full. Hauling a bulky, dirty portable waste tank—often called a “blue boy”—inside your living space is a recipe for odor disasters and sanitary nightmares. Transporting this essential piece of off-grid gear externally is the only practical way to preserve your interior comfort while extending your stay in the wild.

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Why External Waste Tank Storage is Essential for Boondocking

Storing a portable waste tank inside an RV, van, or trailer is an immediate health and comfort hazard. Even after a thorough flush, micro-gaps in valves and plastic walls can release lingering sewage odors that saturate cushions, bedding, and tight living spaces. Keeping this equipment outside ensures that greywater and blackwater residues never contaminate your clean, indoor sanctuary.

Off-grid living demands strict space optimization where every cubic inch counts. A large 28- or 36-gallon tote tank takes up massive real estate inside a wet bath, under a bed, or in a pass-through storage bay. Moving the tank to the exterior of the rig frees up valuable interior storage for solar gear, tools, and provisions that must remain protected from the elements.

Ladder Mount Holder – Camco Rhino Tote Tank Ladder Holder

A ladder mount holder utilizes the vertical space on the rear of your rig, keeping the waste tank completely out of the way of your hitch and bumper. This setup is ideal for travelers who want to keep their ground-level clearance clear of bulky items while making use of an underutilized exterior feature. It lifts the dirty tank high off the ground, away from road debris and potential low-clearance impacts.

The Camco Rhino Tote Tank Ladder Holder is engineered specifically for this task, utilizing heavy-duty aluminum brackets and integrated straps to cradle the tank securely against the ladder rungs. Its design prevents the tank from bouncing or swaying on rough washboard roads, which can damage both the tank and the ladder itself. The hook-and-loop straps combined with a sturdy metal buckle ensure a tight lock that handles highway winds with ease.

• Material: Heavy-duty, rust-resistant aluminum
• Weight Capacity: Up to 50 lbs (empty tanks only)
• Compatibility: Standard RV exterior ladders and most major tote tank brands

Before purchasing, verify that your RV’s ladder is rated to support the weight of the empty tank, as older or degraded ladders can pull away from the back wall under stress. This system is perfect for trailer and motorhome owners with sturdy rear ladders who want an affordable, no-drill storage solution, but it is not suitable for camper vans or rigs without built-in exterior ladders.

Bumper Mount Bracket – Mount-n-Lock SafetyStruts Brackets

Standard RV bumpers are notorious for failing under the stress of added cargo due to thin metal walls and weak factory welds. A bumper mount bracket reinforces the structural integrity of your bumper, allowing you to safely mount heavy items like waste tanks without risking a catastrophic weld failure on the highway. It transforms a flimsy 4-inch square bumper into a highly reliable load-bearing platform.

The Mount-n-Lock SafetyStruts Brackets solve the bumper-failure problem by transferring the weight load directly from the bumper to the RV’s main chassis frame. Made from heavy-gauge galvanized steel, these brackets clamp onto the frame rail and support the bumper from underneath, effectively increasing its carrying capacity. This allows you to bolt on a waste tank carrier or direct mount plates without worrying about fatigue cracks.

• Material: Powder-coated heavy-gauge steel
• Load Rating: Increases bumper capacity up to 400 foot-pounds
• Installation: Bolt-on design requiring basic hand tools (self-tapping screws included)

Check your frame clearance before installation, as some enclosed underbellies may require minor cutting to expose the steel frame rails. This product is a must-have for travel trailer owners with standard 4-inch square bumpers who plan to carry external cargo, but it is unnecessary for motorized rigs with heavy-duty integrated frames.

Hitch Cargo Carrier – MaxxHaul 70107 Steel Cargo Carrier

A hitch-mounted cargo carrier is the ultimate heavy-duty solution for transporting large, heavy items like waste tanks without lifting them high off the ground. By sliding directly into a vehicle’s receiver, it provides a stable, low-profile platform that is easy to load and unload. This eliminates the physical strain of hoisting an awkward, dirty tank onto a roof or ladder.

The MaxxHaul 70107 Steel Cargo Carrier stands out because of its compact 47″ x 20″ dimensions, which perfectly match the footprint of most large portable waste tanks without sticking out too far from the sides of your rig. It features 5.5-inch high side rails that prevent the tank from sliding off laterally, along with a mesh floor that lets road grime and water drain right through. The heavy-duty steel construction is finished with a powder coat to resist rust and corrosion from road spray.

• Capacity: 500 lbs total weight limit
• Receiver Size: Fits standard 2-inch hitch receivers
• Weight: Approximately 25 lbs empty

Because this carrier sits low to the ground, it can reduce your departure angle when navigating steep gas station entryways or bumpy boondocking tracks. This carrier is ideal for truck camper, van, or motorhome owners who have a free hitch receiver and want an effortless loading experience, but it is not recommended for those who tow a trailer unless using a dual receiver setup.

A-Frame Cargo Carrier – Stromberg Carlson CC-275 Bike Bunk

The A-frame tongue of a travel trailer is one of the most underutilized cargo spaces on a towable rig. An A-frame carrier creates an elevated cargo platform directly above your propane tanks and battery boxes, utilizing dead space that would otherwise go to waste. This location keeps the waste tank close to the tow vehicle, reducing rear-end sway and protecting the tank from rear-end collisions.

The Stromberg Carlson CC-275 Bike Bunk is designed to mount securely to the trailer’s A-frame, providing a raised 2-inch receiver that sits safely above your propane setup. Though labeled as a bike bunk, its robust steel construction and high weight limit make it an excellent elevated mounting point for a small cargo tray holding your waste tank. It utilizes adjustable legs to fit varying frame widths, ensuring a tight, custom fit on almost any bumper-pull trailer.

• Weight Capacity: Supports up to 100 lbs on the receiver
• Compatibility: Fits standard A-frame trailers up to 41 inches wide
• Material: Heavy-duty powder-coated steel

Be mindful of your tow vehicle’s turn radius and the trailer’s tongue weight, as adding cargo to the front of the frame directly increases the load on your hitch ball. This setup is perfect for travel trailer owners looking to optimize tongue space while keeping their rear bumper clear, but it is completely incompatible with motorhomes, vans, or fifth wheels.

Heavy-Duty Ratchet Straps – Rhino USA Tie Down Straps

No matter where you mount your waste tank, it will shift, vibrate, and bounce on the road without proper tie-downs. Heavy-duty ratchet straps are the critical link that locks the tank to your carrier, bumper, or ladder, preventing it from becoming a high-velocity projectile on the highway. Relying on cheap bungees or thin ropes is a recipe for catastrophic gear loss and potential road hazards.

The Rhino USA Tie Down Straps are built to survive the harshest outdoor conditions, utilizing an industrial-grade polyester webbing that resists UV damage and abrasion. The ratcheting mechanism features a heavy-duty padded grip that allows you to crank down maximum tension without straining your hands. Their coated S-hooks feature safety clips to ensure they never slip off the anchor points, even when driving over extreme washboards.

• Break Strength: Up to 5,208 lbs (Working Load Limit: 1,736 lbs)
• Length: 1.6 inches wide by 8 feet long
• Included: Pack of 4 straps with soft loops

When securing plastic waste tanks, avoid over-tightening the ratchets to the point of warping or cracking the tank shell, especially in freezing temperatures when plastic becomes brittle. These straps are an absolute necessity for anyone transporting external cargo on any mount, regardless of rig type, though they require a bit of physical coordination to thread and tension correctly.

Roof Rack Cargo Basket – Yakima LoadWarrior Cargo Basket

When ground-level space is non-existent, the roof of your vehicle or camper becomes the logical storage zone for lightweight, bulky gear. A roof rack cargo basket provides a secure, perimeter-walled tray that keeps your waste tank contained and out of the wind stream. This keeps the dirty tank high above road grime and away from potential low-clearance impacts at the rear of the rig.

The Yakima LoadWarrior Cargo Basket is a legendary piece of overlanding gear, constructed from heavy-duty, weather-resistant steel that handles extreme exposure without rusting. Its aerodynamic custom wind fairing minimizes highway drag and cabin noise, while its universal mounting hardware attaches to almost any crossbar style. The basket’s grid design provides endless anchor points for strapping down the tank securely from multiple angles.

• Dimensions: 44″ x 39″ x 6.5″
• Material: Powder-coated steel tubing
• Mounting: Fits round, square, factory, and aerodynamic crossbars

Hoisting even an empty 30-pound waste tank onto a roof rack requires physical strength and ladder access, making this option less convenient for quick setups. This basket is best for camper van conversions, SUVs, and rugged overlanding trailers with roof rack systems, but it is not recommended for tall fifth wheels or motorhomes where clearance is already close to the legal height limit.

Dual Hitch Receiver – MaxxHaul 50022 Dual Hitch Adapter

If you use your single rear receiver for towing a toad, a small trailer, or holding a bike rack, you are normally out of luck for adding a cargo carrier. A dual hitch receiver solves this bottleneck by splitting a single receiver into two stacked openings, allowing you to tow and carry cargo simultaneously. This maximizes the utility of your tow vehicle’s hitch without requiring expensive frame modifications.

The MaxxHaul 50022 Dual Hitch Adapter is a heavy-duty, robotically welded steel adapter designed to handle heavy loads with minimal play. Its corrosion-resistant black powder coat ensures it won’t seize up inside your receiver after exposure to wet roads. By placing the cargo carrier on the top receiver and your tow setup on the bottom, it maintains proper clearance for both systems.

• Capacity: 4,000 lbs gross trailer weight / 400 lbs tongue weight
• Receiver Size: Fits 2-inch receivers on both ends
• Rise/Drop: Provides a 2-inch rise or drop depending on orientation

Always calculate the combined tongue weight of your tow setup and the cargo carrier to ensure you do not exceed the vehicle’s hitch rating. This adapter is perfect for motorized RVers who flat-tow a vehicle but still want to mount a hitch cargo tray for their waste tank, but it is not suitable for heavy-duty towing setups that exceed class III limits.

Spare Tire Utility Mount – Camco RV Spare Tire Carrier

A spare tire utility mount utilizes the heavy-duty mounting studs of your rear-mounted spare tire to create a rock-solid attachment point for cargo. This is an elegant way to mount a waste tank on vehicles like travel trailers, Jeeps, or camper vans that already have a rear spare tire but lack a ladder or a bumper. It places the cargo at an ergonomic waist-height, making loading and unloading incredibly easy.

The Camco RV Spare Tire Carrier mounts directly to standard trailer tongues or bumpers, but its utility-mount adaptations allow it to serve as a solid base for securing bulky gear right against the spare wheel. Its heavy-duty steel construction is finished with a zinc plating to resist rust, ensuring the bolts and brackets won’t seize over years of outdoor exposure. Its simple, rigid design minimizes vibration and keeps the tank close to the trailer body for better aerodynamics.

• Material: Heavy-duty powder-coated or zinc-plated steel
• Compatibility: Fits 4-lug and 5-lug wheels on 4-inch bumpers
• Hardware: Heavy-duty carriage bolts included

Ensure that your spare tire mount bumper welds are strong enough to support the combined weight of the tire and the waste tank, especially on rough terrain. This mount is ideal for small travel trailers and off-road pop-up campers with a rear spare tire, but it won’t work on rigs where the spare tire is mounted underneath the chassis.

Elastic Cargo Net – Powertye 50152 Heavy Duty Cargo Net

While ratchet straps provide the primary structural hold, they can sometimes crush plastic tank bodies if over-tightened, or allow small accessories (like hoses and elbows) to slip out. An elastic cargo net acts as a secondary containment web, wrapping around the entire tank and its attachments to keep everything consolidated. It distributes holding pressure evenly across the tank’s surface, preventing wind from catching loose edges.

The Powertye 50152 Heavy Duty Cargo Net features a tight 3″ x 3″ grid pattern made of premium 4mm latex rubber cord, which retains its elasticity far longer than cheap synthetic rubbers. It is equipped with 6 adjustable ABS plastic hooks that won’t scratch your rack’s finish or damage the plastic waste tank. The hooks are designed with sub-hooks for easy cinching, allowing you to adjust the tension based on how full your cargo basket is.

• Dimensions: 15″ x 15″ (stretches up to 30″ x 30″)
• Cord Thickness: 4mm heavy-duty latex
• Hooks: 6 adjustable, non-scratching ABS hooks

This net is designed for light-to-medium containment and should never be used as the sole tie-down method for a heavy waste tank on the highway. It is an indispensable accessory for anyone using a roof basket or hitch tray who wants to secure both the tank and its messy connection hoses together, but it is unnecessary if you are using a dedicated ladder mount with integrated straps.

How to Secure an External Waste Tank Safely on the Road

Before mounting the waste tank, ensure it is completely empty and that all gate valves, bayonet caps, and vents are threaded tightly to prevent any lingering drips. Position the tank on your chosen carrier with the wheels facing inward or downward, depending on the mount type, to minimize wind resistance. Ensure that no plastic parts are resting directly against sharp metal edges that could wear a hole in the tank wall over miles of road vibration.

Loop your primary ratchet straps through the molded handle of the tank and around the frame of the carrier to create an anchor point that cannot slip off. Tighten the straps until the tank is snug against its cradle, but avoid cranking down so hard that the plastic begins to warp. Grab the tank and give it an aggressive shake; if the carrier or the vehicle moves instead of the tank, your load is secure.

Road vibration has a way of loosening even the tightest straps over time, especially during the first few miles of a trip. Make it a habit to stop and inspect your mounting setup after the first 10 to 15 miles, and at every fuel or rest stop thereafter. Look for signs of strap fraying, shifting cargo, or loose brackets to catch potential failures before they become highway disasters.

Important Weight and Clearance Safety Considerations

The absolute golden rule of external waste tank transport is to never, under any circumstances, haul a full or partially full tank on an exterior mount. A 36-gallon waste tank filled with water weighs over 300 pounds, which will easily snap ladder rungs, collapse bumper brackets, and dangerously alter your vehicle’s tongue weight. Always empty the tank at a proper dump station before hitting the highway, using the external mount strictly for dry transport.

Adding a hitch carrier or bumper mount extends the overall length of your rig and lowers your ground clearance at the rear. This changes your departure angle, meaning the carrier is much more likely to scrape the ground when driving up steep inclines, exiting parking lots, or navigating rugged boondocking trails. Carefully measure this clearance and adjust your driving habits to avoid bottoming out, which can destroy the carrier, the tank, and your rig’s bumper.

A large waste tank mounted on the rear of a vehicle can easily block your license plate, taillights, or turn signals, which is a major safety hazard and a magnet for traffic stops. If your setup obstructs these safety elements, you must relocate them or install auxiliary lights and a license plate holder on the exterior of the carrier. Keeping your safety signals visible ensures that you remain legal on the road while protecting your rig from rear-end collisions.

Managing off-grid waste doesn’t have to compromise your interior living space or peace of mind on the road. By selecting the right external mount and securing it with high-quality tie-downs, you can safely transport your portable waste tank through the roughest terrain. Invest in the proper mounting gear today, and enjoy a cleaner, more organized, and truly self-sustained boondocking experience.