Posted by on 1/19/2026 to
Fresh and Gray Water Tanks
Having a Mobile Support Unit (MSU) or Mobile Emergency Response Vehicle (MEV / MEU) still requires users to follow permit requirements for the local health department or inspecting health department.
Examples of Mobile Support Unit Rules - Verify Your Requirements Before Purchasing
"Mobile support unit" means a vehicle used in conjunction with a commissary or other permanent food facility that travels to and services mobile food facilities as needed to replenish supplies, including food and potable water, clean the interior of the unit, or dispose of liquid or solid wastes.
Ca. Health and Saf. Code § 113833 Added by Stats 2006 ch 23 (SB 144),s 2, eff. 1/1/2007, op. 7/1/2007.
- Plans for the mobile support unit (MSU) needed to service a stationary MFF shall also be submitted for approval prior to construction. The use of a MSU shall be indicated in the operational procedures. A MSU is not approved to service motorized MFFs that conduct food preparation beyond limited food preparation.
Structure and Equipment
Illustrate adequate and separate storage space for food/food items, utensils, trash and cleaning supplies. Adequate storage shall be provided in a manner that will contain all items during transport. All storage compartments on the MSU used in conjunction with an off-site commissary shall be permanently affixed to the MSU.
If used to transport potentially hazardous food, approved equipment to maintain food at the required temperature shall be provided.
Illustrate sufficient storage for all solid food waste with adequate containment during transport.
Illustrate solid wall panels for the placement of the DBA and Certification Sticker on two sides.
Potable water system
The potable water tank shall be of sufficient capacity to replenish the potable water on mobile food facility to be serviced. Provide complete dimensions (length x width x depth) of the potable water tanks.
Illustrate the location of potable water tanks and plumbing lines. All potable water lines shall be of a different size, type, and color to be clearly distinguished from the waste water lines. The potable water lines shall not come into contact with the waste water system or the ground.
Location of potable water pump.
Illustrate approved potable water inlet(s), (recommend Hansen 4HK quick disconnect). All potable water connections shall be of a different size and type to be clearly distinguished from the waste water connections. All connections shall correspond to the mobile food facility to be serviced and the commissary water supply.
Illustrate the potable water overflow line a minimum of 2 pipe diameters (1 inch) below the water inlet draining to the ground. The capacity of the tank will be measured at the level of the overflow.
Waste Water System
The waste water tank shall be of sufficient capacity to replace the waste water on mobile food facility to be serviced. Provide complete dimensions (length x width x depth) of waste water tanks.
Illustrate the location of wastewater tank. All waste water lines shall be of a different size and color to be clearly distinguished from the potable water lines. Waste water lines shall not come into contact with the potable water system.
Location of waste water pump
Illustrate the waste water overflow line a minimum of 2 pipe diameters (1 inch) below the water inlet draining to the ground. The capacity of the tank will be measured at the level of the overflow.
Illustrate the waste tank shut-off valve installed on the bottom of the tank in a manner that will allow for transport. All tanks shall be sloped to drain rain completely.
Illustrate adequate and separate storage space for food/food items, utensils, trash and cleaning supplies. Adequate storage shall be provided in a manner that will contain all items during transport. All storage compartments on the MSU used in conjunction with an off-site commissary shall be permanently affixed to the MSU.
If used to transport potentially hazardous food, approved equipment to maintain food at the required temperature shall be provided.
Illustrate sufficient storage for all solid food waste with adequate containment during transport.
Illustrate solid wall panels for the placement of the DBA and Certification Sticker on two sides.
Potable water system
The potable water tank shall be of sufficient capacity to replenish the potable water on mobile food facility to be serviced. Provide complete dimensions (length x width x depth) of the potable water tanks.
Illustrate the location of potable water tanks and plumbing lines. All potable water lines shall be of a different size, type, and color to be clearly distinguished from the waste water lines. The potable water lines shall not come into contact with the waste water system or the ground.
Location of potable water pump.
Illustrate approved potable water inlet(s), (recommend Hansen 4HK quick disconnect). All potable water connections shall be of a different size and type to be clearly distinguished from the waste water connections. All connections shall correspond to the mobile food facility to be serviced and the commissary water supply.
Illustrate the potable water overflow line a minimum of 2 pipe diameters (1 inch) below the water inlet draining to the ground. The capacity of the tank will be measured at the level of the overflow.
Waste Water System
The waste water tank shall be of sufficient capacity to replace the waste water on mobile food facility to be serviced. Provide complete dimensions (length x width x depth) of waste water tanks.
Illustrate the location of wastewater tank. All waste water lines shall be of a different size and color to be clearly distinguished from the potable water lines. Waste water lines shall not come into contact with the potable water system.
Location of waste water pump
Illustrate the waste water overflow line a minimum of 2 pipe diameters (1 inch) below the water inlet draining to the ground. The capacity of the tank will be measured at the level of the overflow.
Illustrate the waste tank shut-off valve installed on the bottom of the tank in a manner that will allow for transport. All tanks shall be sloped to drain rain completely.
Why is there no NSF logo in the tank?
Can I get an NSF logo on my tank?
Class A Customs was required to remove the NSF logo from all water tanks in June 2020, the tanks continue to be made from the same NSF Certified Materials, built in the same way, built on the same machines, and built in the same building here at Class A Customs. The NSF Company does not allow for end users of NSF Certified Materials to use the NSF logo unless each kind of item that is produced has a certification paid for each year. This would mean every style of tank we make, even though they are made using the same NSF Certified Materials, made in the same process, made on the same machine, we would need to pay to use the logo on each item every year.All of Class A Customs Fresh/Gray water tanks are manufactured using DOW NSF International NSF/ANSI Std 61 approved Medium Density Polyethylene (MDPE) Resin Because Class A Customs was verified to used and continues to use NSF Certified Materials to build our tanks we are allow to link directly to the NSF website materials page and are allowed to state the tanks are made from NSF Certified Materials.
The NSF associate Class A Customs was contacted by and worked with was;
Antonio Acree
Quality Representative, Quality & Compliance
[email protected]
NSF International | nsf.org
789 N. Dixboro Road, Ann Arbor, MI, 48105, U.S.A
1-800-NSF-MARK
Your inspector can validate this information with NSF by contacting them directly.
Ask your local Health Department to provide you with a list of water tank manufacturers that have the NSF logo built into the water tank.
Before you build or modify a unit verify rules and regulations, codes vary by local health departments, not state. We are not aware what tanks or items you will need.
If you have more questions on this please feel free to contact us.
Before you build or modify ----- verify rules and regulations.
Codes vary by local health departments, not state.
We are not aware of the codes or rules. We are not aware of what tanks or items you need.
Codes vary by local health departments, not state.
We are not aware of the codes or rules. We are not aware of what tanks or items you need.
- Ask your local Health Department to provide you with a list of water tank manufacturers that have the NSF logo built into the water tank.
- Forward the documents and tank information provided on the Class A Customs website to your local health department before purchasing to be sure these tanks will pass your local inspection, this is your responsibility.
- Class A Customs NSF Letterthis letter has all fresh/gray tank sizes, part #'s, measurements and fittings, along with material tank is made from.
My health department doesn't care, they won't look... my builders said it is ok... I am just updating tanks.
We hear this and then get the call needing a different tank sent overnight to meet a deadline. It takes very little time to check before and saves you time and money. Forward the documents and tank information provided to your local health department before purchasing to be sure these tanks will pass your local inspection, this is your responsibility.
We hear this and then get the call needing a different tank sent overnight to meet a deadline. It takes very little time to check before and saves you time and money. Forward the documents and tank information provided to your local health department before purchasing to be sure these tanks will pass your local inspection, this is your responsibility.
What does my inspector need when I go to inspections on the tanks?
Class A Customs NSF Letter ( You can print or forward this onto your Health Inspector)
Receipt of Purchase
All tanks have the part number molded into the tank, inspector can verify tank.
Class A Customs NSF Letter ( You can print or forward this onto your Health Inspector)
Receipt of Purchase
All tanks have the part number molded into the tank, inspector can verify tank.
Mobile Shower Units Possible Water Holding Tanks
100 Gallon Fresh / Gray Water Holding Tank | Part # T-10000
