CE 3372 Water Systems Design Lecture 006: Introduction to US EPA-NET

 EPANET Introduction/Workshop  Example problems  Network Design Principles  Introduction to Project Outline

 Install  Example 1 – Flow between two reservoirs  Example 2 – Three reservoir (branched)  Example 3 – Two reservoir, 4 pipes (loop)  Example 4 – Lifting with a pump Workshop

 Sketch a layout on paper  Identify pipe diameters; length; roughness values  Identify node elevations; demands  Supply reservoir (or tank); identify reservoir pool elevation  Identify pumps; pump curve in problem units Model Preparation

 Example 2 – Flow between two reservoirs Example 1

 Example 2 – Three reservoir (branched) Example 2

 Example 3 – Two reservoir, 4 pipes (loop) Example 3

 Example 4 – Lifting with a pump Example 4

 Water Supply System  Includes water supply  Treatment  Facilities  Pumping facilities  Transmission lines  Local distribution network Network Design Principles

 Distribution network - Consists of items designed to convey potable water at adequate pressures and discharges  Pipes  Fittings  Valves  Other appurtenances Water Supply system

 Who?  Personnel within the water company  Engineers / Consultants  Design parameters and regulations?  State board of health  Local city/county health departments  EPA, AWWA, ANSI DESIGN

 Pressure  Velocity  Age  Chlorine concentration  Fire Flow DESIGN REQUIREMENTS

 Pressures  Must be high enough to.. overcome head losses in the system.  But not too high to... prevent damage to fittings and other appurtenances.  Pressure Zones – Set pressurized areas (min and max) within the system by storage, boosters, or pressure control valves.  Can also be due to varying pipe size and topography  May be generated to ensure reliability in meeting fluctuation demands.  System pressures are adapted to requirements.  Hilly areas – booster pumping  Minimum pressures vary state to state  Established by the state’s Health Department / other agency  Fire Marshall may establish additional requirements. Pressure

 Fire Flow Parameters  Each municipality establishes own parameters based on local cond.  Insurance Services Offices (ISO) - Most used “Guide for Determination of Required Fire Flow”  Recommends criteria for  Establishing insurance rates  Classifying mun. with reference to their fire defenses and physical cond. Q = required fire flow in gpm C = coefficient related to the type of construction A = total floor area in ft 2 (excludes basements) Fire flow

 Hydraulic Characteristics  Pressures and discharges are a functions of HC  Length  Size  Condition of pipe  Service Characteristics  Demand as it relates to:  Present and projected population  Economic base  Fire flow  Climate Water supply system

WW ater utility company …… who is responsible for the water quality and operation of thedistribution system. CC ompanies exist in two forms pp ublic entity that..“exists for the health, safety, and welfare of the public”  p rivately owned utility that..provides water for profit WATER utility

Water supply system  Gravity  Dependable  Source of supply must be located well above the city  High-pressure demand for fire-fighting may require pumper trucks  Pump  Least Desirable  Pressures vary substantially with variations in flow  Provides no reserve if power failure  Pump with Storage  Most common  Water supplied at approximately uniform rate  Flow in excess of consumption stored in elevated tanks

Pipe System  Primary Mains (Arterial Mains)  Form basic structure of the system  Carry flow from pumping station to elevated storage tanks  Carry flow from elevated storage tanks to service areas  Laid out in interlocking loops  Mains not more than 1 km (3000 ft) apart  Valved at intervals of not more than 1.5 km (1 mile)  Smaller lines connecting to them are valved

Pipe System  Secondary Lines  Form smaller loops within the primary main system  Run from one primary line to another  Spacings of 2 to 4 blocks  Provide large amounts of water for fire fighting with out excessive pressure loss

Pipe System  Small distribution lines  Form a grid over the entire service area  Supply water to every user and fire hydrants –Connected to primary, secondary, or other small mains at both ends  Valved so the system can be shut down for repairs  Size may be dictated by fire flow except in residential areas with very large lots

Water source (Main Supply) Lake River Aquifer Treatment Facility Treats and disinfects water Meet water quality standards Potable water Transmission Lines Convey water from source – treatment facility facility – network Pumping Facilities Provide energy to move water Intermediate Storage Facilities Stabilize line pressures Reserve for peak demand periods Provide storage for fire flow req. Distribution Lines Convey water from storage – service areas Looped(grid) and Branched Layouts Appurtenances Fire Hydrants. Valves, auxiliary pumps, fittings Water SUPPLY system

Water Use Systems  Spatial and temporal distribution in support of human habitation  Water supply/treatment/distribution  Waste water collection/treatment/discharge  Capacity is based on POPULATION served  hydraulic dominated designs

Water Use AND DEMAND  Water Use  Consumptive  Municipal  Agricultural  Industrial  Mining  Non-consumptive  Hydropower  Transportation  Recreation  Water Demand  Quantity that consumers use per unit of time  Ex: Mgpd  Depends on population, climate, industry and economic factors

Water DEMAND  Residential  Single-family, multi-family (apartments)  Water for drinking, landscape, swimming, fires, street cleaning, etc.  Usually two demand peaks (morning and evening)  Commercial  Motels, hotels, offices, shopping centers  Usually less peak demand and less varied than residential  Industrial  Chemical plants, food processing plants, mines  Water for fabrication, cooling, petroleum refining, etc.  Water use depends on type of industr.

Assigning Demand  Assign demand using network models (links and nodes)  Network models contain nodes that represent a multitude of actual connections.  While conceptually possible to model to every single connection, it is discouraged because  Model is hard to maintain  Small errors may go unnoticed  The operation of any single connection is not well known.

Network Types  Branch  No circulation  Has terminals and dead-ends  Water in dead-ends is stagnant  Disinfection residual  Corrosion

Network Types  Grid/Loop  Furnishes supply from more than one direction  Water circulates  Disinfection is more effective.  Water “age” in system is younger (fresher).  In case of water main break, fewer people are inconvenienced

Network Types  Loop vs. Branch during network failure  Every link in a branch system is a single point of failure that isolates all downstream nodes.  Not with loop, only main supply line is failed

 Semester design project is to conceptual design a water distribution system and a storm water sewer system for a small residential development  Hydraulic analysis for both systems to demonstrate that the systems will supply/convey as sufficient capacity Project

 Demand estimation is used to determine how much water a system is likely to use (for sizing reservoirs and tanks  Flow rate estimation (a plumber’s perspective) is used to determine how much capacity a system should be able to provide Estimating Flow Rate

 How Much Water Can You Actually Get?  Flow Rates are measured in gallons per minute (gpm).  For our purposes, we will talk about the amount of water that you can get through a pipe at a velocity of 8 feet per second (a standard velocity used to engineer a plumbing system).  Plumbing diameter will limit the flow rate you can get – the larger the pipe, the more water you can get. A home with 1 ″ plumbing can use substantially more water than a home with 3/4 ″ plumbing. How Much Water ? Meter to house Inside home

 1. Think about the maximum number of fixtures and appliances you might operate at the same time.  2. Look at the chart to see how many gallons per minute each device requires.  3. Add up the flow rates for all the devices you selected.  You just figured out the PEAK FLOW RATE that you need.  Now, think about your continual water use, or water use that may run for more than 10 minutes. Add up the fixtures again, and you just calculated your SERVICE FLOW RATE. How Much Needed? (1)

 resources/water/drinking-water/best-practices/water- system-planning-estimating-water-use How Much Needed? (2)

 Estimate need per connection to size the system;  Run a hydraulic model at these values to size pipes  Estimate demand to evaluate how the system is likely to perform in terms of pressure zones and such  Run a hydraulic model at these values to check pressures – no fire flow  Run a hydraulic model with fire flow to check minimum pressures Using the estimate

 Several readings on server will be useful: Readings

 Pumps  Review how to size  How to simulate in EPANET  NPSH considerations Next Time