GAUTENG DEPARTMENT OF INFRUSTRUCTURE DEVELOPMENT BUILDING ASSESSMENT REPORT WET SERVICES ABSA BUILDING

Transcription

1 Report for Department of Infrastructure Development Wet Services Preliminary Report: ABSA Building October 2014 GAUTENG DEPARTMENT OF INFRUSTRUCTURE DEVELOPMENT BUILDING ASSESSMENT REPORT WET SERVICES FOR ABSA BUILDING OCTOBER 2014

2 Report for Department of Infrastructure Development Wet Services Preliminary Report: ABSA Building October 2014 Table of Contents 1. INTRODUCTION Design Criteria and Specifications Scope of the Services Scheme Report PROJECT SUMMARY Plumbing and Drainage Systems Water storage tank Water reticulation Drainage reticulation Solutions Water storage tank Cold water reticulation Hot water reticulation Drainage reticulation Green star building Rain water harvesting Grey water harvesting Other green initiatives already required by SANS Part XA Water saving sanitary fittings Water meters Alternative energy... 6

3 1. INTRODUCTION Absa building, located on the corner of Albertina Sisulu Road and Fraser Street, Johannesburg, Gauteng (see Locality Map): Figure 1 - Locality Map The project brief, as issued by Gauteng Funding Agency (GFA), was to conduct an initial assessment of the building s plumbing and drainage infrastructure and systems and to provide recommendations regarding the repairs and renovations of the building. 1.1 Design Criteria and Specifications This project will be implemented in compliance with all the requirements of the National Building Regulations and SANS10400, with specific focus on Part P (Drainage) and Part XA (Energy efficiency for building) of the regulations. 1.2 Scope of the Services Scheme Report This report deals with the wet services to be implemented based on the existing systems and proposed architectural changes to the building. 1

4 2. PROJECT SUMMARY 2.1 Project Description The project is comprised of a multi-storey building, which has been divided to accommodate three separate tenants. Two of the tenants enter the building off Albertina Sisulu Street (Absa tenants and Absa bank), whilst the last tenant (Road and Rail Agency) enter the building off Fraser Street. The building has two basement parking levels, space for the bank, office space, as well as two roof levels. The previous Absa bank tenant occupied the entire ground and first floor level, allowing only a very small reception for the other tenants. Therefore, whilst the other tenants did have a ground floor reception, their actual office space only began on the second level. The gross building area for the ABSA Building is approximately 6934 sqm. The current assessment of the existing building entailed inspecting the present state of sanitary, plumbing and drainages services within the building. Furthermore, the building does not comply with two elements of the National Building Regulations, SANS 10400; which relate to universal accessibility and the latest energy efficiency regulations. 3. Plumbing and Drainage Systems 3.1 Water storage tank In terms of cold water storage, this building has very little capacity. There is a small sectional steel tanks located on the highest roof level. On the same roof there is a concrete water tank as well. The concrete tank is empty and may not be in working order. All valves and pipe work is still intact, however some of the fittings show signs of corrosion. Fig. 1 Concrete water tank Fig. 2 Small sectional steel water tank 3.2 Water reticulation Cold water transferred to the roof water tank via a municipal main supply. No booster pumps or tanks were found in the basement. From the roof, the water is supplied to the building via gravity. The sanitary ware is in a poor condition and out-dated. All the fittings consume considerable amounts of water. Fig. 3 Sanitary fittings Some of the bathrooms on the occupied floors have been refurbished, however, the fittings show signs of fatigue. 2

5 Fig. 4 Sanitary fittings in refurbished bathrooms Beside the one geyser located in the kitchen, no other hot water generation equipment was found. The geyser may have served the kitchen only. It is no longer operational. Fig. 5 Geysers in kitchen on upper floor 3.3 Drainage reticulation The main drain pipes all mainly ran down in two separate locations. The drainage on one side of the building ran in ducts, whereas on the other side, the drainage ran down the external façade. The cast iron pipes are extremely rusted. There is an existing sump in the basement. The drainage reticulation is at the end of its lifespan and must be replaced. Fig. 6 Drainage reticulation Fig. 7 Sump in basement Fig. 8 Open ended drain pipe Fig. 9 Drainage reticulation in duct 3

6 4 Solutions The remedial work required to meet the minimum national standard and reinstate the plumbing and drainage systems is recommended and a high level budgetary cost for the remedial work is presented. 4.1 Water storage tank The existing water tanks should be drained and inspected for any damage or rust internally, then disinfected if deemed to be in good condition. Apply the following disinfection procedure to any storage tank: a. Remove all visible dirt and debris from the inside of the storage tank; b. Fill the storage tank with clean water and then drained until empty; c. Refill the storage tank with clean water and add a solution of sodium hypochlorite to the water until a free residual chlorine level of 50 mg/l in the water is measured; d. Leave the chlorinated water in the tank for not less than 1 h and not more than 3 h, after which (in turn) open each terminal fitting served by the storage tank, starting at the one closest to the tank and working progressively away from the tank, until the water discharged begins to smell of chlorine, then close each terminal again; e. Do not allow the storage tank to become empty during the discharging described in (d); refill and re-chlorinate the tank as in (c), as necessary; f. When the discharging is carried out on the terminal fitting furthest from the tank and the smell of chlorine becomes evident, measure the level of free residual chlorine in the water discharged. If the concentration of free residual chlorine is less than 30 mg/l, repeat the disinfecting process, starting from (c); and g. Keep the tank and pipes charged with the chlorinated water for at least 16 h and then thoroughly h. Flush them with clean water until the free residual chlorine level at any terminal fitting does not exceed that present in the clean water from the mains. In the case of pipework under pressure, apply the following procedure: a. Carry out chlorination treatment through a properly installed injection point, using a chemical pump at the start of the installation until the measured free residual chlorine at the end of the installation is at least 20 mg/l; and b. Leave the chlorinated water in the system for at least 24 h, after which flush the installation with clean water until the free residual chlorine level in the water, measured at the furthest point from the injection point, does not exceed that present in the clean water of the mains. NOTE 1: Disinfection should be compatible with the pipe system manufacturer s specifications. NOTE 2: Should the use of alternative disinfection systems be considered, the process should be performed under the supervision of and the results certified by a suitably qualified specialist personnel as specified by the manufacturer of the materials and equipment. NOTE 3: Following the performance of the disinfection process, it is recommended that a water sample be obtained and submitted for quality analysis in terms of the requirements given in SANS and SANS Alternatively, cold water storage tanks should be replaced to ensure a continuous water supply to the building in event of a municipal main failure. 4.2 Cold water reticulation The cold water reticulation system and pipe work is still in working condition. The system could be thoroughly inspected and tested for signs of severe rust. Some of the galvanized pipes have rusted through over the past years, these sections must then be repaired. 4

7 We recommend that all galvanized pipes be replaced with new galvanized pipe or polypropylene random copolymer (PPR) / multilayer pipe (MLP) to be used in terms of green star and ensuring the future longevity of the installation. All cold water reticulation should be replaced to ensure longevity of the system. All the installation must be in compliance with SANS part Hot water reticulation We recommend that all hot water pipes be replaced with a polypropylene random copolymer (PPR) or multilayer pipe (MLP) to be used in terms of green star and ensuring the future longevity of the installation. All the installation must be in compliance with SANS part 1 To comply with the part XA building regulations, 50% of the hot water generation energy must consist of alternative energy i.e solar panels or heat pumps. The hot water vessel is past its life expectancy and should be replaced. 4.4 Drainage reticulation The existing cast iron is in working condition, however due to the age of the installation the cast iron pipe work would be corroded internally. Green star rating will be improved when adherence is given to the PVC mineralization category with in the green star requirements. We recommend using HDPE pipe as a replacement. Installation to be in accordance with SANS part 2 and the national building regulations part P 5

8 5 Green star building In attempts to get a 5 green star rating on the building, we suggest the following: 5.1 Rain water harvesting Rainwater is collected by capturing rain via the roof and then storing it for purposes of WC flushing, irrigation or fire prevention. Water is captured on the roof though gutters or specialized rain water capturing systems. The water is then stored in a water storage vessel. From there the water will be filtered by a rain water treatment plant and stored in a separate storage vessel. The storage vessel will be large enough to supply the intended demand for 5 days. The water is then pumped back into the building for the purpose of intent. The water produced by the water treatment plant in not safe for human consumption, thus should be kept separate from the domestic water supply. 5.2 Grey water harvesting Grey water is another good way to conserve water. However, grey water is only recommended for irrigation purposes. Similar to rain water it is stored in a storage vessel, then treated and again stored in a separate vessel from where it will be pumped. Even though the water is treated by a treatment plant, there are many pathogens that remain in the water. These pathogens may cause many health issues within the building it is used when consumed by the occupants. 5.3 Other green initiatives already required by SANS Part XA Water saving sanitary fittings The building regulations require that sanitary fittings within the building be of the low flow type: WC to have 3 and 6 liter dual flush options Wash hand basins to have a maximum flow rate of 6 liters per minute Showers to have a maximum flow rate of 9 liters per minute Urinals to flush 0.8 liter per flush Water meters Water meters must be installed on each section of the building to detect higher usage levels. With this information the efficiency of the water reticulation system can be measured and faults can easily be detected Alternative energy 50% of the energy used through the conventional resistive heating of water shall be of an alternative source: Solar Air to water heat pumps Gas Coal 6