Please note: these minutes are being published to inform the local community as to the status of the repairs to the Cape Flats Waste Water Sewerage Works, this first posting has the minutes from 2 meetings 1st in Black then 2nd in Red

Notes from a meeting at CFWWTP ( Tuesday 8^th July 2014)

Present: Michael Toll, Nizaam Henry, Richard Cammell, Stewart Penney.

Notes from a meeting at CFWWTP (Tuesday 23^rd September 2014)

Present: Nizaam Henry, Richard Cammell, Stewart Penney. Apologies: Michael Toll.

Overview

This meeting was a reinstatement of the meetings between the waste water operational management and representatives of the Zeekoevlei Peninsula residents to provide the residents with information on actions being taken at the CFWWTP to correct the operational problems that are causing bad smells and the dumping of sludge.

The reports back at the FBEP committee meetings were not effective hence the formal reinstatement of these meetings, the substantive content will be tabled at the FBEP committee meetings.

The meeting was very open and comprehensive and it was very pleasing to hear that there is a recognition by the relevant city officials of the critical need to maintain the WWTPs in good order. Testified by the planned capital expenditure of +- R300 million over the next few years.

Incoming sewerage

1. We discussed the reticulation of the waste water and MT stated that although there is provision for the sewerage in the pipes from Raapenberg (RP1 & RP2) to be diverted into the Cape Flats pipes (CF1 & CF2) this is NOT happening at present. This has been subject to some conflicting information at previous meetings.
2. 3 of the screw pumps are functioning – No 1 at +- 90% (to be serviced), No 2 covered and working (don’t have a %), No 3 not working, No 4 at +- 90%. All 4 screws to be replaced 1 at a time – the first No 3 by February ’15 (both concrete and mechanical). This is all approved. No 2 is to be switched off for electrical work – 4 days.
3. There are 2 back up submersibles – 1 working and 1 in for servicing. The hired submersible has been serviced and is back and the other (owned) is in for service. Each pump is capable of pumping 35/40 mlpd.
4. Occasionally there is still some overflow into the ponds. Not for some time.
5. The plan is to replace the bark scrubbing system with a bio filtering system like the one at Athlone – documents to go out to tender (already out?) from the BSC (supply chain) as scoping and design done. Disappointingly the documents have not gone out to tender yet despite MT understanding they had 2 months ago at our last meeting. This is taking an inordinately long time.
6. It is intended to cover the sump, screw pumps, and all flow channels to the PSTs where there is turbulence. It was questioned whether this could be incremental rather than all done at the end. MT agreed this should be discussed between operations/engineers/contrators. He pointed out the danger of covering before extraction because of gas build up. No timetable was tabled. Refer note in g) below for time table.
7. It was agreed to lower the level of covering perfume being used. The perfume suppliers have been asked to come on site and give recommendations as to the appropriate level. MT stated that they are prepared to stop perfuming altogether if the residents request it – this is noted but not to be actioned until discussed with residents. The perfuming has stopped (though this had not been discussed with residents as agreed at our previous meeting). There is an alternative (expensive) perfume that could be used. It is currently being used in the sludge beds (complaints from Pelican Park residents). (Note from the last FBEP committee meeting: MT – “The contract regarding the odour control for the inlet is on track with the entire process expected to be completed in August/September 2015”.)
8. Any broken/damaged manhole covers on the incoming pipelines must be repaired.
9. PST’s : 2,4 & 5 are OK, 7 & 8 are new, and 1,3, & 6 are being done. Refurbished concrete wall, and new bridges (with wall mounted motors as opposed to a large motor in the centre driving the bridge around). The civil and mechanical contractors have been appointed and the first bridge is being manufactured. Completion – April 2015. This will bring the PST capacity back up to the 200 mlpd design capacity. Disappointingly the information given at our previous meeting was incorrect insofar as the civil contract has NOT been awarded – there is an appeal pending from an unsuccessful tenderer. No 3 has new mechanicals and it is planned to SIKA the top of the wall as a temporary measure to smooth it pending full civil work. 1 & 6 to be done (mechanical work complete) waiting on the civil work. Future planned maintenance would be to refurbish one PST (in the summer and takes 2 weeks). In discussions on capacity it was explained that retention time is critical to the process (not just PSTs) and that lack of capacity leads to reduction of retention time and hence poor quality sludge output.
10. SST’s – the mechanical and civil contractors have been appointed (same as the PST) on site September, also the hub change to be wall sited. This is a 3 year contract (the contractor is working on all WWTP sites not just the CF) mechanical and civil. There are 22 SSTs – 12 old and 10 new. 2 of the old ones will be refurbished (reworked) by winter as the contractors are currently working at Athlone. The plan is to rework 2 at a time, empty the SST cut into base, and rework input feed pipework to feed from the centre of the SST. Same comment as for the PSTs for capacity and retention time – currently there is insufficient capacity for the correct process retention time.
11. Contract for the blowers awarded. (There are 4 blowers – 3 are working.)Actually only 2 are working. One has had the motor/gearbox fixed but not the pump – will take 6-8 weeks – does the pump come from England? (Should have been done at the same time??), and another has to have the transformer fixed and service motor.

Sludge

1. The 2 centrifuges are with Andritz engineers in Nelspruit for refurbishing/balancing. This has been done and the centrifuges will be released on payment (R2 million+). The contract is ‘turn key’ contract and the Andritz must install and ensure that the centrifuges work. The decision to try this route rather than the belt press route as recommended by Orecon was based on timing and cost, plus a belief that Andritz has improved it’s ability to do the work correctly. They should be installed and running by year end latest, hopefully earlier. Plus training given to on-site staff for operation and maintenance. This was most disappointing as the centrifuges are still at Andritz and not yet complete (85%) pending payment. In other word no progress from the last meeting despite assurances at that meeting from MT that 1 centrifuge should be in and running by year end. This slowness to be raised by RC and SP at the FBEP meeting if not with other CT authorities. Bearing in mind that this route (refurbishing the centrifuges) was chosen on timing and cost!!
2. 1 centrifuge can handle 100% capacity so there is capacity with 2 to maintain and repair.
3. There are 4 centrifuges but the other 2 that dewater the sludge before it is pumped to the digesters are not needed as they were for pelletalisation. The current operational focus is to stop sludge going onto the drying beds rather than on pelletising.
4. The rented belt press is still on site but can only handle +- 1/3 of the load. Ie it can produce 16 – 17 cubes per day. Now down to 15/16 cubes per day – hence more sludge flowing to the beds than before – a deteriorating situation.
5. The digesters were upgraded to be more efficient and generate more methane, this is a 2 part process but the process has not worked properly since the upgrade. The first part of the process is working fine but the second that produces the methane is not. There is a water ingress problem – the source of the excess water is not known for certain. This excess water is interfering with the bio process – brings down the ph and produces less methane. There is a contract (+-R200k) to bypass pasteurising which is where operations believe the water is coming in. There is not apparently a water ingress problem. The contract is in place to bypass the pasteurising vessels which are in very poor shape. And the intent is to inject steam directly into the bottom of the digesters. Due to inadequate retention times upstream the digester process is compromised. Trials with different flow rates through the valves (increasing the solid content) look promising – then the valve controls can be automated.
6. Because of the high level of sludge being deposited in the drying beds there has been no rotation allowing for drying to take place. Hence the beds are more like lakes. Once the sludge inflow to the beds stops then rehabilitation can take place by first pumping out surplus water and recycling it through the plant. This is probably a 10 year plan!
7. Pasteurization (heating system) Tender advertised. Is this the direct steam injection into the digesters?

General

1. The number of maintenance staff on site has been drastically reduced from what it was and the function substantively centralised. The operational personnel and the centralised maintenance staff do report upwards to the same Director but the operational staff have no direct authority over the maintenance personnel. Observations from our site visit on the 21^st February 2014 (RC &SP) show that there are some serious shortcomings in the current arrangement. Also a significant health and safety risk. This continues with a minimal staff complement on site.
2. RC & SP to plan a feed back to the residents in the first half of September. These notes, once agreed, are to be put on the Peninsula website and hence available to all residents.