Maintaining the AQUA-MARE Marine Sewage Treatment System
A. Blockages and Failures
The operating software monitors the operation of the various pumps and will sound an alarm if a major pump suffers a significant failure e.g. the pump impellor becomes blocked. Similarly, the system also monitors the height of fluid within the various tanks and will sound an alarm if an over-full situation occurs in one or more tanks.
Most over-full situations will result from the Holding Tank Discharge Pump having been turned off while in a prohibited-discharge area e.g. a boat harbour. Simply switching the Discharge Pump to On or Auto (once discharge is permitted) will rectify this situation and allow the system to again operate normally.
Any other failures or blockages need to be investigated and rectified prior to using the toilet/s, to prevent overfilling of the tanks.
B. Replacing the Liquid Chlorine
Liquid chlorine is the normal form of providing disinfection for your system. The amount of fluid remaining in the tank should be checked on a regular basis.
At installation, the size of your liquid chlorine tank was registered within the system software and the system does monitor the volume of liquid chlorine solution being used. It will normally set off an alarm at 75% utilisation, 90% utilisation, and 100% utilisation. However, the calculation of liquid chlorine used/remaining is a mathematical approximation, and regular checks of the remaining chlorine should be conducted, in case of a more rapid utilisation of chlorine than expected.
The level of active chlorine available as a disinfectant within the liquid chlorine solution also degrades with age and heat. Do not store any more chlorine on board than is necessary and replace the liquid chlorine solution within the chlorine storage tank on a regular basis if it is not being used.
Note: The amount of liquid chlorine being added by the system to the effluent being transferred from the aeration tank to the Treatment/Holding Tank, can be adjusted to suit the expected chlorine strength of the remaining chlorine solution. However, it is recommended that the effluent not be over-treated with chlorine as this will have an adverse effect on the surrounding environment as well as the discharge pump, and will create objectionable odours. See you Operator’s Manual for further details.
C. Non-organic and Other Materials
In certain applications e.g. commercial systems, the tanks may have to be pumped-out due to the amount of non-organic material being flushed down the vessel’s toilets. Your AQUA-MARE biological digester will not consume any non-organic materials and may have difficulty with some ‘foreign’ organic materials as well. These may build up in the aeration tank (or the grinder tank if fitted) and need to be manually removed.
Fats, oils, chemical, etc., should also not be flushed into the system and may also need to be removed if excessive quantities are introduced into the system.
D. De-Commissioning
Short Term:
To stop the system from operating for a short period e.g. up to 1 week, empty the collection/grinder tank (if fitted) and the holding tank (but not the aeration tank), and remove the power from the system. Store the liquid chlorine in a dry safe place until needed. Note: Turning the MSTS ‘off’ in this manner will result in the aerobic bacteria dying off within the aeration tank and the biomass will turn septic (anaerobic). This is acceptable for a short period only due to the subsequent production of methane and hydrogen sulphide gases, but is not recommended long term.
To recommission the system, empty the ancillary tanks (if not already empty) and restart the system. With the addition of new sewage and oxygen to the retained biomass, new aerobic bacteria will form, which will create the new biomass and as with a new start up, the aerobic biomass will redevelop.
On start up, the settled biomass will be stirred up by the mixing action of the aeration process, and oxygen will again be absorbed by the contents of the system. Please note that the system may produce objectionable odours during this phase as the aerobic bacteria redevelop.
Longer Term:
If the vessel or the MSTS will not be used for several weeks or more, the MSTS can be turned off, and the various tanks pumped out (including the aeration tank) in a discharge-permitted area or into on-shore waste disposal facilities, and preferably the tanks refilled with clean fresh water. Remove the liquid chlorine solution from the chlorine storage tank and dispose of safely and thoughtfully.
Note: Simply turning the MSTS ‘off’ will result in the aerobic bacteria dying off and the biomass will turn septic. This is acceptable for a short period but is not recommended long term, due to the potentially explosive gases that can be produced.
To recommission the system, empty all tanks except the aeration tank. If freshwater flushing is used, the aeration tank can be left full of fresh water; if saltwater flushing is used, the freshwater should be emptied from the aeration tank and the aeration tank refilled with clean seawater.
Refill the chlorine storage tank with new liquid chlorine solution.
With the addition of new sewage, to the aeration tank new bacteria will form which will create the new biomass and as with a new start up, the biomass will redevelop. | 
