Note: You can also download the Supply List and Build Information.
Overview
These days keeping clean is everything. When you work out in the field, it can be hard to find a place to wash your hands, and rental companies can’t keep up with the demand for hand-wash stations. This portable hand-washing station features a single bar sink and faucet, fresh-water and grey water containers, and an on-demand pump powered by rechargeable batteries.
This station was built by folks at the Historic Preservation Training Center to meet our needs to get back in the field, but keep our workers safe.
Here’s the final product:

So, how did we build it? We’re glad you asked! You can follow the information below or download the Build Information and Supply List.
How it All Fits Together
Here are some detailed photos of the final build:








Equipment List
We provide specifics of what we used, but also included notes about how to improve on it. You can click the links and buy exactly what we bought. Or better yet, check your storage area for components you might already have.
Item (click for webpage) | Price | General Notes | Build Notes |
Metal Cabinet | $229.99 | Cabinet to house sink and components. Metal for exterior use. Ended up having lots of holes for mounting shelves so interior will get wet in driving rain. | Only install upper shelf. Cut shelf down to approximately 6″ wide with back lip to house battery and extra fuses, other accessories. Other cabinets would also work. |
Cabinet Casters Set | $57.99 | For cabinet. Mobility and raising cabinet height to 36″. | Consider using full swivel lockable aftermarket casters. Factory set comes with to fixed casters making full 360-degree movement difficult. |
Single bar sink | $86.94 | Mount in hole cut in top of metal cabinet | These are undermount sinks ended up working fine. They were secured with premium liquid nail and sealed with silicone. You could also consider top mount sinks if you’re building additional. |
12v On-demand pump, built in pressure switch | $67.95 | Install inside cabinet mounted on plywood. | Pumps at 2.9gmp which is too much for a wash sink so we reduced the flow with a sink aerator. You could also consider a lower flow option; make at 2.0gpm and drawing lower amp hours. |
12v, 12ah SLA AGM Rechargeable batteries | $29.67 | Install inside cabinet on upper shelf. Velcro in place and install stop screw to prevent movement during transportation. | Spade terminals. Good sealed battery with no off gassing. Will require charging past 50% use to maintain life. |
Smart Trickle Charger | $29.29 | For charging. Could be used to run units of AC power with battery always trickle charging. Will not overcharge. | Alligator clamps. |
Touch free faucet, or equivalent | $88.99 | Counter mount, battery powered | Mounted in back of cabinet to plywood secured to inside of cabinet. |
Touch free soap dispenser | $50.00 | Counter mount, battery powered | If building again, most likely would not use. With installed soap cartridge, unit is approximately 2′ long limiting interior cabinet space. Additionally, most components are plastic and have concerns about longer term durability. Cartridge needs to be removed during transportation. |
Paper tower dispenser, multi-fold, towels | $39.95 | Mount outside side of cabinet | If building again, would consider other options that are more sealed. Towels get wet during rails, even when wrapped with plastic wrap. |
Fresh water container, 6 gallon | $8.50 | Install outside cabinet, one extra per cabinet to swap as needed. Container is smaller than gray water to prevent overflow. | If using a different soap dispenser, you could potentially mount this inside cabinet. |
Gray water container, 7 gallon | $17.99 | Install inside cabinet | Could also consider using 7-gallon bucket from Uline. We wanted the containers to look different to not confuse with fresh water. Also easily sealable for transportation of gray water for disposal. |
Water container lids | $2.25 | Lid with spout hole for fresh water and gray water if not using aquatainer. | Can also be sealed for transit. |
Low Flow Aerator, .5 gpm | $3.14 | Reduce flow of water to limit changing of water tanks. Still provide adequate water flow for hand washing. | Variable reduced flow could also be achieved with shutoff valve post pump assembly. |
In-line fuse holder | $7.42 | 2-20 amp, 12V DC, standard blade | Install between switch and battery |
10 amp standard blade fuse | $4.45 | 10 amp, 12V DC standard blade fuse | Install in fuse holder |
Inlet strainers | $2.20 | Washer for Female GHT threaded connection with screen | Install as strainer in garden hose fitting in inlet hose |
Bolt on tie-ring | $1.60 | Provides a place to secure with chain | Mount on backside |
Hose barb, hose bib connection | $5.44 | Straight adapter for 1/2″ hose id, 3/4″ GHT Female | Install on end of 1/2″ reinforced vinyl inlet hose |
Expandable grommet | $6.37 | Side of cabinet for batter charger connection, pack 25 | Optional to mount in side of cabinet to provide access to plug in smart charger for battery charging |
Rubber grommet | $10.72 | Side of cabinet for inlet hose | Silicone in place |
Illuminated switch | $4.02 | LED SPST ON/OFF Short handle toggle switch, illuminated green when on | Install in recessed switch plate |
Recessed switch plate | $3.08 | Cole Hersee toggle guard | Install in side of cabinet, recessed to protect switch to pump |
Battery capacity gauge | $4.88 | 12V battery capacity indicator. Used to indicate battery charge and to show when battery is at 50% to recharge. | Install on inside of cabinet next to battery. Could punch a hole and install next to switch. |
Misc. plumbing and electrical | $60.00 | Miscellaneous hoses, clamps, wiring and electrical connections. | Misc. supplies needed for connections including but not limited to hose clamps, supply lines, and wire splices, heat shrink, spade connections, silcone, adhesive, and nuts and bolts. Plywood was scrap. |
Total Costs | $822.83 |
Questions
If you have any questions, you can contact Trevor Thomas at trevor_thomas@nps.gov.