RV Grey and Black Water and Waste Holding Tanks

RV holding tanks are replacement tanks for wastewater systems: grey water from sinks and showers, and black water from the RV toilet. This collection is for grey and black water holding tanks; for potable water storage, shop our RV fresh water tanks. If you are starting with the question rather than a part number, read how many gallons an RV holding tank holds before comparing listings.

Choose a replacement by matching the old tank's capacity, outside dimensions, drain and fitting locations, and available clearance. The gallon number alone is not enough: two tanks with similar capacity can have different shapes, outlets, or plumbing layouts.

How to choose an RV holding tank

1. Measure the space. Record length, width, and height of the old tank and the opening where it sits. Check clearance around frame rails, straps, plumbing, and nearby components.
2. Match the layout. Compare the drain, outlet, fill, vent, and sensor locations with the replacement listing. Confirm whether the listing is tank-only or includes fittings.
3. Match the part number. Search the old label or molded number, then compare it with the OEM references in the product title. Examples in this collection include EPI, H-series, ERV, and Alpha references.
4. Confirm before ordering. If the model year, fitting layout, or available space is uncertain, call 574-675-6919 or email help@elkhartrvparts.com with photos and measurements.

Verified RV holding tank examples

These examples are taken from current product listings. Use the individual listing for the complete fitting and drain details; dimensions below are listed as length × width × height in inches.

Need help with fitment?

Have the old tank's measurements, photos of every fitting, and any label or part number ready. We can help compare the available replacement listings, but the final fit depends on your RV's space and plumbing layout. Call 574-675-6919 or email help@elkhartrvparts.com before ordering when those details are unclear.

Browse the products below to compare capacities, dimensions, and OEM references. You can also use the RV Tank Finder when you are shopping by measurements, or add RV tank fittings and parts if the replacement needs a different fitting layout.