Water, Sewage & Effluent May June 2019 - Page 42

• the rational design; • the deem-to-satisfy-rule; and • the agreement certificate. The deem-to-satisfy rule of design was intended for a building where an engineer is not required due to it not being complex in terms of size or height, for example. The deem-to-satisfy rule of design is basically a ‘one-size-fits-all’, whereas the rational design is an ‘exact fit’ or ‘fit-for-purpose’, which could mean more or in some cases or sometimes less than the deem-to-satisfy-rule. These are the original definitions of the deem-to-satisfy rule and rational design, but somewhere, somehow, rational design came to mean ‘or equal’. If it must only be equal then the rational is not relevant anymore, they cancel one another out – and this doesn’t make sense. The fire water system The design of the fire water system in terms of the NBR is SANS10400-W (also referred to in SANS10400-T and SANS10252-1), is a design code of practice which was changed to a Standard under the Water Act and contains a section for fire water. It is important to note that SANS10252-1 was promulgated under the Water Act and not under the NBR Act and is therefore not the mandate of the Building Control Officer, however there is reference to this document as a standard. The fire water section of this document refers to a situation where a building is of such height ‘where the fire department cannot reach’ and that the 40 of this property and therefore, the requirements for infrastructure design cannot be considered compulsory within the jurisdiction of the NBR. The design standards for water infrastructure end at the boundary of the property and cannot be applied within the property boundary. To ensure that no confusion sets in, it is very important to understand the institutional framework of the NBR. The NBR is based on the NBR Act of 1977. It consists of regulations, which are compulsory and are contained in Annexures, and it describes the performance of systems. Then there are a number of ‘deem- to-satisfy-rules’, which are basically a ‘recipe’ of how to comply with the regulations. These are, however, not compulsory, and the owner can choose to apply them. There are three methods of design and construction to follow in order to comply with the regulations namely: Fire departments have insisted that the owners of properties must provide large volumes of water on their properties, specifically reserved for firefighting. owner must provide pumps to reach the height of the building. The focus element here is the pumps. However, large pumps that must pump from ground level directly out of a water supply pipe to the top of a high-rise building are not acceptable, and not allowed by local authorities. Therefore, a break pressure tank is required for this purpose. It was agreed, in conjunction with the fire authorities, to provide a quantity of water in tanks for the pumps – the size of which is determined by fire officers to be 25 000ℓ. It is not intended that the size of this tank hold the total quantity of water to fight a fire, but rather that the tank is filled constantly from municipal fire hydrants via a fire hydrant with a dry pipe to the tank while the pumps are in operation. You cannot separate the fire water system of a building from the municipal water infrastructure, yet this ‘stipulation’ falls under two different acts, two different authorities and two different legal responsibilities. Some fire officers refer to SANS 10090 to enforce their requirement of large fire water storage tanks and pumps and it seems they prefer water as the only medium for fighting a fire. The building fire water system under the NBR and building standards, depends on the municipal bulk water infrastructure supply and fire hydrants to ‘fight a fire inside a building’. There is a dire need for all role players and stakeholders to come together and find consensus on the issues and problems and find acceptable and cost-effective solutions to satisfy everybody in the supply of water and the use of water for fire protection. The important role players / stakeholders include: • Municipal water engineers • Municipal fire officers • Municipal town development • Building control officers • The NRCS Local by-laws • The SABS The local by-laws also refer to SANS10252-1. The problem is that the local authorities clearly state in their by-laws, in terms of the Water Act, that their water is provided under three conditions, as follows: • SAICE • SAIMECH • The Architect Association • Developers • Insurance companies • NO guarantee of water. • NO guarantee of pressure. • NO guarantee of quality. These three elements must be secured by the owner at his own cost, if they wish to do so. Water Sewage & Effluent May/June 2019 It is important that these solutions be applicable nationally and take into consideration solutions where water supply is a problem and how to find and apply alternative solutions.  www.waterafrica.co.za