Understanding the Model Aquatic Health Code (MAHC): Feed Equipment

In Blog, Chemistry, Model Aquatic Health Code by David Jerkins

If you missed the last post where we went over flow meters, click here.

Today, we’re going to be going over some sections of: 4.7.3.2 Feed Equipment

Gone are the days of someone manually adding chemicals multiple times a day and struggling to maintain a proper balance. With today’s technology, equipment is used to maintain chemical levels in a body of water with more precision and oversight than an operator can provide. These sections mandate that all commercial facilities must use automation and feed systems to maintain pH and active disinfectant.

4.7.3.2.1.2 Feeders & Devices

Chemical feeders must be used for pH and disinfectant feeds. Do not rely on hand feeding these chemicals. Feeders must only be used for the chemicals approved by the manufacturer. This means don’t use a pump to feed acid if it’s not rated for acid.

4.7.3.2.8A Automated Controllers

This section simply states that an automated chemistry controller must be used on aquatic venues and must be rated NSF-ANSI 50. Importantly, it also requires that operation manuals be available that include such things as basic maintenance (Probe cleaning, etc.) Knowing how to properly maintain a controller is essential to all pump room maintenance. The controller is the heart of the system, deciding what and when things will happen. Negligence can cause tracking issues which could lead to over or underfeeding, failure of safeties, and much more. Having operating procedures will help prepare staff.

4.7.3.2.8.4 Set Point

A setpoint means that the controller must be capable of maintaining a certain level of a value. You can’t just set a timer. Modern controllers give you a target, and it will feed chemicals until it reaches that target, or setpoint, and then stop feeding.

4.7.3.2.1.3 Interlock Controls and No or Low Flow Deactivation

In the event of a “No Flow” or “Low Flow” event, it’s crucial to have safety features in place to stop any chemicals from feeding. The recirc pump should be interlocked to equipment electrically so if the pump stops equipment such as chlorine generators, UV systems, etc will stop production. Additionally, either a flow switch connected directly to the equipment, or the flow switch in a chemistry controller that can kill power to equipment should be used. Pumping chemicals during a no flow event is a serious safety concern. Always have safeties in place to prevent equipment from running when there is no flow. The MAHC requires a minimum of two in place.

4.7.3.2.1.3.2 Visual Alarm

It’s important to have alarms to notify staff in the event of something like no flow. Most commonly, the controller can send out an alarm, and depending on the controller, can even send email or SMS notification to let operators/managers know when something has occurred. This is important in case bathers need to be removed from the water immediately.

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