Question 1.
Week 1 Tutorial
Question 1.
For a catchment in the Penrith Council area of size 100 ha, estimate the available amount of stormwater for non-potable uses with in the catchment.
Obtain monthly rainfall data for Penrith Lakes (Station ID 067113) AWS from BoM website. Calculate the average annual rainfall and then use this value to estimate the amount of stormwater available for non-potable uses.
Assume the losses as given below:
St = 10% of the rainfall
Sm = 12% of the rainfall
Gwr = 8% of the rainfall
Ep = 10% of the rainfall
Et = 5% of the rainfall
Ro = 25% of the rainfall
Question 2. (20%)
A lake receives 150 m3/d of stormwater. Concertation of total phosphorus (TP) in the stormwater that is entering the lake is 3 mg/L. On an average the 40% of the inflow gets evaporated and the rest flows through the lake.
Determine the concentration of TP in the stormwater flowing out of the lake.
Also, within the lake, if 20% of TP gets consumed by the plants that are present in the lake, determine the concentration of TP in the stormwater effluent from the lake.
Question 3:
It is required to design a wastewater treatment system for a small city. The flow measurements are not available. However, the following data are available:
Houses = 1,200 (25% residing in highrise, 25% in low rise; 25% in typical home; 15% in better home; and 10% in luxury home). No. of people in each house can be taken as 3.5.
Hotels = 2 (total 500 guests and 100 employees)
Department store = 2 (total 5 toilets and 50 employees)
Restaurants = 2 (total 500 meals a day)
Shopping center = 1 (100 employees and 1000 parking space)
Medical hospital = 1 (500 beds and 50 employees)
Day school = 1 (with cafeteria, gym, showers and 1000 students)
Estimate the daily wastewater flow rate that can be expected from this city.
Question 4:
Sewers are to be installed in a camping area that contains
a developed campground for 200 persons;
lodges and cabins for 100 persons, and
resort apartments for 50 persons.
Assume that persons staying in lodges use the dining hall for 3 meals per day and that a 5 seat cafeteria with 4 employees and an estimated 100 customers per day has been constructed. Daily attendance at visitor centre is expected to be 50 percent capacity. Other facilities include a 10 machine Laundry, and a 20 seat cocktail lounge. Determine the wastewater flow rate from this camping area in m3/d.
Week 1 Practical class
Introduction to NearmapsSelection an area (containing both residential and commercial properties) of approx. 10 ha.
Count the number of residential, commercial and institutional properties.
Determine the possible stormwater inlet points by using the vertical profiles option in the Nearmaps.
Sustainability and Risk Engineering
Week 2 Tutorial Question
The catchment of a subdivision has only one inlet at the southern end. The catchment area is located in Penrith. Average slope for the catchment is 5%. Average length of the catchment (tip to the inlet) = 80 m. Determine the rainfall intensity of a 10% AEP storm that should be used to calculate the stormwater flow for designing a conduit. Assume n* = 0.092 (sparse vegetation).
Table 1. Rainfall Intensity for different AEP
Duration, min Rainfall Intensity, mm/h
Annual Exceedance Probability (AEP), %
63.2 50 20 10 5 2 1
1 119 137 192 231 270 323 365
2 97.3 110 152 181 211 252 285
3 90.2 102 141 169 197 235 266
4 85.1 96.8 135 161 188 225 254
5 80.7 92.1 129 155 180 216 243
10 64.1 73.7 104 126 147 176 198
15 53.3 61.4 87.1 105 123 147 165
Also, determine:
Design flow for a catchment area of 10 ha. C can be taken as 0.67.
Diameter of a pipe for carrying the stormwater (Mannings n can be taken as 0.013)
Depth of flow in a natural channel carrying the stormwater (Mannings n can be taken as 0.024). Assume the width of the channel as 1.0 m.
Week 3
Tutorial Questions
Question 1.
For a treatment system which is designed as a part of Water Sensitive Urban Design, the following influent and effluent concentrations are obtained. Calculate the removal efficiency for each of the parameters.
Parameter Influent concentrations Unit Effluent concentrations Unit
Gross pollutants (GP) 2 kg/m3 0 kg/m3
TSS 150 mg/L 20 mg/L
TP 5 mg/L 3 mg/L
TN 10 mg/L 2.5 mg/L
If the flow is 20,000 m3/yr, determine the amount of the pollutants removed from the stormwater.
Question 2.
For the pond of area of 2000 m2 with an average depth of 4 m, determine the stormwater available for consumptive use. Need to maintain the permanent volume of 2500 m3 in the pond. The pond is located in Richmond RAAF area.
Question 3.
What should be length of a swale for reducing the TN concentration from 20 mg/L to 10 mg/L?
Question 4.
Compare the life cycle costs for the following GPTs at current prices. All prices given are for 2002. Assume 10 ha catchment area and life period 50 yr.
GPT type Capital cost Maintenance cost
Rocla Downstream defender $24,000 $20/ha/month
Stream Guard - catch basin insert $290 $200/yr
Stream Guard - passive skimmer $60 $200/yr
Enviropod 100-500 m screen $530 $200/yr
Ecosol RSF100 $666.50 $200/yr
CSR Humes Humeceptor $30,000 $20/ha/month
Rocla Cleansall $85,000 $14,400/yr
Ecosol RSF 1000 $8,000 $12/ha/month
Baramy $27,500 $12/ha/month
CSR Humegard $34,500 $14,400/yr
Source: https://wiki.ewater.org.au/display/MX1/Appendix+H%3A+Costing+information
Sustainability and Risk Engineering
Week 4 Tutorial
Question 1:
There is a tiled roof on a residential house in Sydney with 70 m2 roof area and is draining into a single downpipe. The householder would like to capture and store the roof water in a rainwater tank. Estimate the maximum quantity of rainwater per year that can be potentially harvested.
(Assume annual rainfall in Sydney region 1164 mm/year; runoff coefficient as 0.9 for the tiled roof)
Question 2:
There is a metal roof on a residential house in Perth with 200 m2 of roof area and is draining via four downpipes. The house owner is planning to capture the rainwater using a 2 kL rainwater tank. It is expected to use a first flush device, which will divert 150 L of runoff each time it rains. Determine the quantity of rainwater per year that can be harvested (water savings).
BoM station for rainfall data: Perth Metro (ID 009225); Use the daily data for 2016.
Runoff coefficient of 0.8 for metal or tiled roofs.
Daily demand is 1.5935 kLCompare this amount with the maximum that can be harvested and the total household demand.
Question 3:
For the data given in Q2, if the householder would like to capture and store the roof water in a rainwater tank of capacity 5 kL, estimate the number of days per year, the rainwater may be used as supplement to the main water supply.
Compare the water savings between Q2 and Q3.
Question 4.
Calculate the quantity of irrigation water required for irrigating a sports field of 3 ha in area. The following data may be used:
Grass type: Kikuyu
Evaporation data: BOM station ID: 009021 (Perth Airport)
Period: July 2019 June 2020
Week 4 Practical
Using the network created in earlier classes, compare the change in the removal rate in TN and TP by changing the design parameters in each of the below cases:
Case 1: Bio-filter: increasing the surface area by 2 timesCase 2: Swale: increasing the length by 2 times.
Week 5 Tutorial Questions
Question 1
Find the unknown quantity in the following cash-flow diagrams, assuming compound interest.
Question 2
In an irrigation district, an irrigator can purchase an extra share (allotment) which entitles the holder to 0.7km2-cm of water per year in perpetuity. If the share costs $1,600, what is the cost of one km2-cm of water to the irrigator? Assume an interest rate of 8%.
Question 3
A public utility commission requires that a trust fund be established by a private company wishing to build and maintain a water treatment plant for a small city. The company must deposit enough money to build the plant and then to operate and renovate the facility in perpetuity. The plant will cost $10,000,000 to build, has an annual operating expense of $600,000, and must be renovated every 20 years at a cost of $1,000,000. The trust fund earns 6% interest. What amount must the company put in the trust fund?
Sustainability and Risk Engineering
Week 6 Tutorial Questions and Computer Lab Exercise
Question 1.
Estimate the present worth of the total cost of the operational energy usage for a house whose current heating and cooling requirement is 25,000 kWh/yr, over a period of 50 years. The split in the energy consumption for various categories is as given in below:
Heating and cooling Lighting Appliances
Split in the energy consumption 45% 25% 30%
You may use the following data in your calculations:
Tariff = 25 c/kWh
Interest rate = 6%
Question 2: Based on the following data calculate the power that can be converted from the wind by a Horizontal Axis Wind Turbine (HAWT)
Blade length, l = 52 m Wind speed, v = 12 m/sec
Air density, = 1.23 kg/m3 Power Coefficient, Cp = 0.4 Hints:
The swept area of the turbine can be calculated from the length of the turbine blades using the equation for the area of a circle:
= 2
774700180975The following equation may be used in your calculations:
Where, P = Power (Watt); = Density (kg/m3); A = Swept Area (m2); v = Wind Speed (m/s)
1427159156153
Question 3.
797105412220The power coefficient is not a static value as defined below and it varies with the tip speed ratio of the turbine.
Tip speed ratio is defined as:
= (Blade tip speed/ wind speed)
= (),
60
Where D = diameter of the turbine
Given that the rotational speed of the turbine is 15rpm, calculate the energy using the following equation and complete the table:
Energy = Power Time
980772209908
CP vs curve for wind turbine
Hints:
Given that the rotational speed of the turbine is 15 rpm, calculate using the above two equations and fill it in the following table. Then read the corresponding value of Cp using the graph below. This Cp value can then be used to calculate the power at that wind speed using appropriate form of Betz Law. Finally, calculate the energy using the provided equation. Please note, there are crosses in the table where the wind turbine would not operate due to the wind speed being too high or too low.
Question 4:
For a small hydro system the turbine efficiency is 80%, drive efficiency 96% and generator efficiency 90%, if we have a relatively low gross head of 3.5 metres, and a turbine that could take a maximum flow rate of 4 m3/s, what is the maximum power output of the system?
Question 5:
Calculate the Annual Energy Production of a hydropower system if the maximum power output of the system is 65.4 kW.
Question 6:
Calculate the annual solar energy output of the below photovoltaic system
A = Total solar panel Area (m) 40
r = solar panel yield (%) 17%
H = Annual average irradiation on tilted panels (shadings not included)* 1150
Question 7:
In a Photovoltaic (PV) SYSTEM, the reactive power is 42.5 W and the active power is
56.7 (var), calculate the power factor for the mentioned PV system?
Question 8:
98217478471800By 2050, Germany is planning to get all its energy through renewable sources (see following graph). With the current prices per unit (e.g. price at 2015), estimate the likely price for the electricity produced in 2050. Assume current price of different sources as shown in the below table. You may use average prices.Sources of energy USD/MWh
Hydrogen 100-160
Import 230-250
PV 60-250
Wind 40-80
Geothermal 50-100
Hydropower 30-100
Biomass 90-110
CHP 100-170
Gas & oil 50-80
Lignite 100-150
Hard coal 90-100
Nuclear energy 90-130
Computer Lab Exercise
Question and answer sessions regarding the use of MUSIC.
Discussions about the project.
Sustainability and Risk Engineering
Week 6 Tutorial Questions
Question 1.
A family consumes 15 kg of honey in a year. The honey can be bought from the supermarket as either Pack 1 or 2, as shown in Table 1. Calculate the amount of waste produced in terms of plastic containers by the family. If the disposal cost of the plastic is $1000/tonne, calculate the overall cost of the product and waste disposal per year.
Table 1. Options for purchasing honey.
Parameters Pack 1 Pack 2
Amount of Honey, g 500 340
Price, $ 8.60 6.90
Weight of the empty plastic containers, g 75 65
If these two options are continued for the next 25 years, what is the total present worth of all the costs for both options? You may use an interest rate of 5% in your calculations.
Question 2.
A loan of $15,000 for six months yields $1,350 in interest. What is the approximate annual rate?
Question 3.
A student loan with a simple annual interest of 3% is to be repaid in 5 years. The total interest paid on a student loan was $500. What was the amount that was initially borrowed?
Question 4.
A project has an initial cost of $99,500 and uniform annual benefits of $12,480. At the end of its useful life of 7 years, its salvage value was $29,500. What would the projects present worth be at a 9% interest rate?
Question 5.
What amount of money was deposited 25 years ago at a 5% interest rate that would now provide a perpetual payment of $15,000 per year?
Sustainability and Risk Engineering
Week 7 Tutorial Questions
Question 1:
Using the data given in Tables 4.1 and 4.2 (uploaded under Week12/References), calculate the operating cost in terms of $/person for Regional-metropolitan area Bus Rapid Transit (using the data from Table 4.1), Rail Rapid Transit (from Table 4.1), Regional Rail (RGR) (from Table 4.2), and Personal Motor Vehicles (Table 4.2). Compare the results. Assume cars per track for RRT and RGR as 50 ad 25, respectively. Unit conversion: 1 mi = 1.61 km
Note: Regional trips are for specialised services, such as those at a medical specialty centre. Other regional trips may be to a special recreational attraction, such as a sports centre, zoo or museum. Facilities that either employ large numbers of people, such as regional hospitals, or attract large crowds, such as sports arenas, should be encouraged to locate in areas accessible by transit for the sake of both visitors and employees.
Question 2:
Using the data given in Tables 4.4, calculate Greenhouse Gas (GHG) emission (Scope 1) from scooter, motorcycle, Very small auto for city, SUV for highway, 12 m diesel transit bus, LRT, regional rail, intercity rail, and high speed rail. Compare the results. Identify the mode of transport that has lowest and highest CO2-e emissions per 100 km travelled.
Note: For types of emission, see Section 2.2 of National Greenhouse Account Factors (uploaded in Reference material folder)
For fuel combustion emission factors, see Table 4 of National Greenhouse Account Factors
Question 3:
Using the data given in Tables 4.5, compare Greenhouse Gas (GHG) emissions (Scope 1) from different air passenger modes (e.g. Cessna 172, DHC 8-300, Boeing 737, Airbus 320, and Boeing 777-200 ER) and water passenger modes (e.g. Passenger ferry, Passenger and car ferry, luxury ship). Identify the mode of transport that has least CO2 emission per km travelled and per person.
Assume:
CO2 emission from aviation fuel = 3.15 kg/kg of fuel
Density of aviation fuel = 800 g/L
