PUBLIC HEALTH ENGINEERING 1. PREAMBLE The primary purpose of this document is to define the basis of design for the facility in terms of Public Health Engineering (PHE) for the development. The task of achieving a trouble free plumbing installation in a Building would involve three major components like • • •
A technically correct, simple and user friendly design. Selection of the right materials. Adopting sound installation methods, employing skilled manpower and supervisory staff.
A standard plumbing design can be broadly being divided into the following categories. Water supply, treatment, storage and distribution. Sewage collection and disposal. Storm water disposal and rainwater harvesting. 2. WATER SUPPLY Water Supply for the proposed Hospital building assumed to be from Municipal source. Tanker water is also anticipated for shortfall of Municipal water, since the supply is intermittent. Depending on the characteristics of the tanker as well as Municipal water quality the water treatment system will be suggested. 3. SEWERAGE SYSTEM It is proposed to connect the sewer from the hospital to the Municipal Drain 4. STORM WATER DRAINAGE SYSTEM Storm Water Drainage System shall be designed to dispose off the rainwater from building terrace and external catchment area within the site premises. Rainwater recharging soak pits shall be proposed all along the storm water drain in regular interval. Excess runoff water during peak rainfall will be diverted in the nearest external drain. STANDARDS ADOPTED National Building Code of India (NBC-2005) Plumbing Engineering Services Design guide- Institute of plumbing American society of Plumbing Engineers Data Book All Relevant Indian standards
OMEGA Hospital Kurnool - Preliminary design
2. WATER SUPPLY SYSTEM 2.1
WATER REQUIREMENT
Domestic water requirement for the proposed Hospital is envisaged in Annexure I. Domestic water requirement per day TOTAL FRESH WATER REQUIRED PER DAY 2.2
: :
18Cum 18Cum
WATER RESERVE (STORAGE)
Based on the various requirements as explained in Annexure I, two day storage (Raw water storage-one day & Treated water storage one day) shall be provided for Hospital domestic & HVAC purpose in addition to fire fighting static water reserve. The summary of the storage is as follows: Description Fire water tank
Capacity (Cum) 100
Location
REMARK
For sprinkler & hydrant system, raw waterDomestic quality from bore well Raw water tank 18 Below ground For & Flushing raw waterDomestic For quality from & Flushing bore well Softened water tank 18 Terrace raw water quality from bore well The bore well water will be connected to the fire static tank, from where it overflows to raw water tank. 2.3
Below ground
WATER TREATMENT
The quality of water supplied to building is in accordance with the requirements, specified in IS10500- 1991- DRINKING WATER SPECIFICATIONS depending on the analysis of the water; the treatment process will be worked out. The Hardness of bore well water is about 1200 mg/L. For domestic and flushing water supply (8hr operation-18 cum/day ), basic treatment with pressure sand filter, activated carbon filter, softener and disinfections by chlorine dosage is proposed. The treated domestic water will be treated further by RO for drinking. 2.4
WATER DISTRIBUTION SYSTEM
The Cold and Hot water to the fixtures shall be distributed as follows: a. b. c.
Domestic cold water to toilets, Flushing water for toilets shall be by means of gravity from overhead tank on terrace. RO water to Drinking water cooler separate system. Hot water to all toilets, shall be by mean of Hot water Geyser.
OMEGA Hospital Kurnool - Preliminary design
3. SEWERAGE SYSTEM Soil pipes from top most floor fixtures shall be connected to vertical soil stack in the shaft. Similarly the waste outlets from the washbasin and shower drain shall be connected to waste stack. There shall be soil stacks and waste stacks in double toilet (back to back) shafts and one soil stack and one waste stack in single toilet shaft. In each shaft connecting a 110mm SWR Pipe line from soil lines at each floor, is lead up to terrace as vent through roof. The vents of soil and waste stacks also to be taken above terrace level. The soil and waste stacks connect to soil and waste Man hole at upper basement. •
MATERIALS USED The make of Sanitary fixtures are Hindware / Parryware and CP fittings are ESS ESS respectively. The network is designed considering SWR pipes and fittings for internal and UPVC pipes for external sewage. 3.1 BASEMENT DRAINAGE Soil pipes & waste pipes outlets in the upper Basement & lower basement shall be connected to the sewage collection sump located in the lower basement. Necessary sewage pumps with auto float switch for automatic operation are proposed to dispose the sump water to the nearest external manhole at ground level (one pump will be working and other pump will be 100% standby). Basement ramp water is collected by sump. Necessary dewatering pumps with auto float switch for automatic operation are proposed to dispose the sump water to the nearest drain. 3.2 RAIN WATER DISPOSAL The rain water system is separated from sewage system. Separate down takes and collectors provided for rainwater disposal from terrace. The down takes are designed for maximum intensity of rainfall as 70 mm/hr. The material of pipe proposed to use for rainwater piping shall be U PVC type ‘A’ pipes and fittings as per IS standards. Suitable rainwater harvesting / recharging system shall be worked out as per the norms of the state. • Soak pits shall be provided all along the storm water drain at suitable intervals to harvest the surface run-off. The soak pits shall be covered with pebbles & broken brick bats for percolation. •
The entire terrace rainwater from the roof would be disposed through suitable rain water pipes and connected to collection chambers. Roof rain water shall be diverted into different recharge wells, through a network of interconnecting pipes. The recharge wells are located near the parking area and lawn.
The excess rainwater (after percolate through soak pits) from the building and all landscaped areas would be collected by suitable drain and disposed to the nearest external storm water drain .
OMEGA Hospital Kurnool - Preliminary design
3.3
SUBSOIL DRAINAGE SYSTEM
Sub soil drainage is proposed for basement grade slab & consists of perforated PVC pipes with geo filter fabric. The pipes are laid in slope covered with geo filter fabric. Gravel is filled over the pipes to enhance the collection of sub soil water. The sub soil drainage pipes are terminated at the collection sump dedicated for subsoil drainage.
ANNEXURE – I PLUMBING AND SANITARY SYSTEM WATER DEMAND NOTE: Per capita consumption considered is based on NBC, Part-9 and factors based on daily usage
Sl.No.
No of BEDS / No of BEDS
1
50 50
A
No.of Persons per BED
Total Populati on
1
50
No. of lpcd {Litres/ day} DOME STIC
No. of lpcd {Litres/d ay} FLUSHI NG
No. of lpcd {Litres/d ay} DRINKI NG
TOTAL WATER {Litres/d ay} DOMES TIC
TOTAL WATER {Litres/d ay} FLUSHI NG
TOTA L WATE R {Litres /day} DRIN KING
300
45
15
15000
2250
750
18000
15000
2250
750
18000
50
Hence Domestic water demand/day (in liters):
18000
say (in cum):
say (in cum):
18
Under Ground Water Storage (in liters): {Designed for 2 days rqmt} B Water Storage: Centralised U.G.Sumps
