5.3 BLACK WATER SYSTEM

The black water system installed on board the yacht consists of a 170 litre (45 gal) capacity black water collection tank, positioned amidships.

The system vent is located at the stern, on the port side.
Before being discharged outside, the vented air passes through an activated charcoal filter to eliminate unpleasant odours.

The tank is equipped with a level switch which starts the discharge pump when it detects a high black water level, and deactivates it once the level has decreased.
The level switch measures the water level inside the tank and sends alarm signals to the main electrical panel and to the WC control pushbutton panels.

The electric WC system is supplied and protected by the magneto-thermal switch located on the main electrical panel; it must be activated in order to allow WC operation.
A pump, in the engine room, empties the tank via a suction line, which discharges through the vent located at the stern, on the port side.

The pump has two operating modes, automatic and MANUAL, which can be selected via a control on the main switchboard.
In “AUTOMATIC” mode, reaching the mid-level threshold triggers the pump, which remains active until the low level threshold is reached.
In “MANUAL” mode, the “MANUAL DISCHARGE” control on the main switchboard must be activated to start the pump.
The pump remains active until the low level is reached.
If the level is lower than the low level, the pump will not start, not even pressing the “MAN” button.

CAUTION

Within 12 nautical miles from the coast it is forbidden to discharge the black water tank into the sea; it is necessary to keep the discharge pump inactive and to exclude the automatic activation.

The option of unloading the sewage tank at the shoreside and transferring its contents to the on-shore sewerage system is the solution with the least environmental impact, which should be adopted whenever the yacht is moored in an equipped place.

CAUTION

Before leaving port, check the level indicators of the sewage tank on the synoptic on the bridge in order to perform suction from the shore if necessary.

Procedure for emptying through the shoreside nozzle.

• Handle the hose by paying attention not to soil the teak, and dampen it ahead of time.
• Correctly fit the outlet for shore drain by means of the screw connection.
• Take advantage of harbour services for sewage intake with vacuum system.
• Once the operation is completed, disconnect the hose correctly by paying attention again so as not to soil the teak. If necessary, rinse.

Before entering shore, you should check the tank level and decide whether you should discharge at sea or use the port facilities by checking in advance if the your destination port is equipped for tank emptying through the aft starboard nozzle.
To increase the reliability and safety of the system, in case of a fault in the black water pump, it is possible to drain by means of the grey water pump. Under such conditions, it is necessary to ensure the proper opening of the concerned manifold valves.

CAUTION

During the suction black water from the shore is strictly prohibited to:

• Use the toilet;
• Press the command button then operate the pump discharge overboard.

WARNING

Before use, make sure:

• Enable the utility by setting the WC system magneto-thermal on the main electrical panel to ON if necessary;
• The absence of the retention tank high level warning light on the bridge.

CAUTION

It is advisable to routinely monitor the sewage level via the indicators on the main switchboard in order to optimise the use of the retention system in accordance with local environmental regulations.

CAUTION

The suction outlet, is labelled with a “WASTE” indication, in order to avoid the accidental penetration of liquids such as water or fuel.

CAUTION

In case of sinking hazard, if escaping condition allow you this, close the ball valve of the black water drain.

CAUTION

Totally empty the system and the black water tank before the lay-up period in order to prevent any problems with freezing.

CAUTION

For all pleasure yachts, drain at sea of on-board toilets is forbidden inside harbours, landings and moorings dedicated to yachts’ anchor riding, and also within the limit of beaches visited by swimmers, as stated in the single regulations of the Port Authorities.

CAUTION

Direct sea discharge can only be carried out in the event of an emergency.

The holding tank is equipped with a sea water washing system. In order to wash the tank, you have to open the valve concerned, located on the tank door, and start the concerned pump.

This operation has to be performed periodically at a variable time interval, according to the use of the tank.

In addition to this, we recommend constantly checking the filling of the tank, so as to disconnect the pump when necessary.

WARNING

The valve for washing the holding tank must always be closed, except for during washing operations. If the valve remains open, the tank can be flooded and sea water can be boarded.

WARNING

The holding tank washing must be performed only in compliance with legislation in force, in the harbour, only under provided it is connected to the disposal facilities on land.

WARNING

When using chemical products, follow the manufacturer indications meticulously and use the suitable protection devices.

DANGER

Holding tank washing must be performed by experienced personnel and followed carefully until the tank is empty.
An excessive pump operation can cause the intake of a large quantity of water with consequent overfilling and bilge flooding.

Black water system diagram: