® Rainer Abendt Dr.- Ing. Rainer-Werner Abendt Nuremberg Contact: Wastewater Workshop in Nairobi 29-th August till 03-rd September 2011 Sewer Systems

® Rainer Abendt A Recap of the previous module indicated that:- Sewage purification systems are necessary for health. Because supply of clean water to the population is indispensable for health provision. (National Water Services) But sewage systems are also important for protection of groundwater or river water. Why? Because we need river or ground water to produce drinking water ! Sewer Systems

® Rainer Abendt Sewer Systems Sources of raw water in Bavaria Millions. m³/yr % value groundwater from wells ,8 groundwater from springs ,5 bank filtrate, recharged groundwater48.35,1 surface water24.22,6 Total

® Rainer Abendt Effluent Standards (emission) Water Quality Standards (imission) Education Standards: labours and academic Health and Safety Standards Sewer Systems

® Rainer Abendt Treatment plant Urban area Evolution of water crowd: - Sewer construction Evolution in sewer network: - By-laws Evolution of Water quality: - Sewer operation First step! Without Stormwater Drainage -auslässe Legal Orders Sewer Systems

® Rainer Abendt Treatment plant Urban area Evolution of water crowd: - Sewer construction Evolution in sewer network: - By-laws Evolution of Water quality: - Sewer operation Or First step! With separate Stormwater Drainage Effluent in a river -auslässe Legal Orders -auslässe Legal Orders Sewer Systems

® Rainer Abendt Are the stormwater drains connected to the trunk sewer? If not, where does the stormwater drain to? Urban area Evolution of water crowd: - Sewer construction Evolution in sewer network: - By-laws Evolution of Water quality: - Sewer operation Storm- and Wastwater mixed Stormwater Effluents Treatment plant -auslässe Legal Orders -auslässe Legal Orders Or First step! Sewer Systems

® Rainer Abendt Wastewater disposal (Discharge and treatment) Administration: Finances; Personnel By-laws: Connection approval; Industrial monitoring; Cost covering Sewer construction: General drainage; Sewer network expansion; Sewer operation: Maintenance, repair, operation/control of storage space and outlets (provisions under water law) Sewer Systems

® Rainer Abendt Sewer Systems Pipe Varieties in Nuremberg, Germany. These are examples of types of pipes needed for various transmission works In selecting a pipe material for sewer service, the design engineer must evaluate standards for materials, products and systems The standards must meet international specifications and must have passed Proficiency Testing Programs for quality assurance.

® Rainer Abendt Technical Standards of Materials  Product &Testing Standards guarantee quality.  Check the:- pipe diameter Pipe Material Pipe thickness Sewer Systems

® Rainer Abendt First WASPA Annual International Conference 8-9th September 2011, KICC Grounds, Nairobi, Kenya DEN = Technical European Norms Free trade

® Rainer Abendt Examples of Standards Quality of on Water Materials:  CEN TC 155 „Plastics piping systems“ “  CEN TC 163 „Sanitary appliances “  CEN TC 164 „Water supply “  CEN TC 165 „Waste Water Engineering“  CEN TC 203 „Cast iron pipes “  CEN TC 208 „Elastomeric seals“  CEN TC 230 „Water analysis “  CEN TC 308 „Characterization of sludges“ Sewer Systems

® Rainer Abendt Example: ‘Visual inspection coding system, Sewer Systems

® Rainer Abendt Wastewater types (Q WW ): 1. Domestic wastewater (Q D ) such as: shower water swimming pool water flushing water faecal water 2. Commercial and/or industrial wastewater (Q Ind ) such as: production water treatment water cooling water 3. Infiltration water (Q IW ) 4. Stormwater (rainfall) (Q R ) 5. Melt water Daily amount of wastewater, normal in Europe: average: l / (per individuaI per day) frequently: > 300 l / (per individual per day) due to increased amounts of infiltration water (Q IW ) Sewer Systems

® Rainer Abendt Parameters in Wastewater pollution (raw sewage): Inhabitant-related loads in raw wastewater BOD 5 : 60 g/(per Individual per day) COD: 120 g/(per Individual per day) filterable solids: 70 g/(per individual per day) P tot : 1.8 g/(per individual per day) N tot : 11 g/(per individual per day) N tot in raw wastewater mainly as TKN TKN (Total Kjeldahl Nitrogen): Norg + (NH N) undissolved matter: 30 % dissolved matter: 70 % Sewer Systems

® Rainer Abendt Sewer Systems Wastewater pollution (raw sewage): Concentrations of minimum parameters in domestic raw wastewater: BOD 5 : mg/l COD: mg/l P tot : mg/l N tot : mg/l

® Rainer Abendt The wastewater discharged into the sewer system should not possess the following characteristics: 1. Free acids (pH values 8.5) 2. Salts in high concentrations 3. Strong poisons (toxic substances, e.g. Cu ions) 4. Oils and greases (mineral oils) 5. Hazardous and explosive gases (e.g. methane, petrol fumes) 6. Odorous substances (e.g. sulphides from leather processing) 7. Large quantities of suspended or heavy settleable solids 8. Radioactive substances (e.g. from hospitals) 9. High Temperatures (over 35 °C) 10. Heavy discoloration (e.g. from the textile processing industry) Sewer Systems

® Rainer Abendt Sewer Systems RW FW SW The daily variation of waste water % Wastewater Infiltration Water Pipe capacity for stormwater

® Rainer Abendt Sewer Systems Cost Reduction: You can reduce your treatment costs, if you ensure non-soiled wastewater does reach the sewer network at all. In a mixed sewer net (rain and wastewater) you can reduce your costs by building a storm water tank at a quarter the distance from the start of the trunk sewer with a drain time of 10 to 15 minutes in the channel.

® Rainer Abendt Sewer network of Nuremberg Treatment plants Sewer network Stormwater tank Sewer Systems

® Rainer Abendt Sewer Systems Schematic profile

® Rainer Abendt Sewer Systems Diagram

® Rainer Abendt Water quality of the river Sewer Systems

® Rainer Abendt Demands on water quality (Europe): COD BOD 5 Ammonia N tot P tot Suspended Solid Why Sewage Purification ?

® Rainer Abendt Laboratory operating data Demands on the sludge Legal orders Secure disposal Government control Automatic monitoring Legal orders Treatment plant (Process system) Product 2 " Sludge" Product 1 „Clean Water" Urban area Evolution of water crowd: - Sewer construction Evolution in sewer network: - By-laws Evolution of Water quality: - Sewer operation Administration Personnel Documentation Financial management Sewer Systems ?

® Rainer Abendt How then does a Treatment Plant look like ? Sewer Systems