Wastewater

Treatment Plant Proposal

for Marfa, Texas

May 13, 2016

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Table of Contents

Overview……………………………………………………………………..3

Letter of Intent………………………………………………………3 Company Background……………………………………………4 Team Members…………………………………………………….5

Problem Statement and Project Objectives………………………7 Problem Statement………………………………………………..7 Project Objectives……………………………………………….…7

Design Flow Rate and Assessment of the Characteristics……8 Growth Population………………………………………………..8 Flow Rate……………………………………………………………..8

Characteristics of Raw Wastewater…………………………….……9 Layout, Land Area, and Future Expansion…………………….13 Preferred Location of the Treatment Plant………………….…14

Location Requirements………………………………………..14 Proposed Location…………………………………………….…14

Pump selection……………………………………………………………16 Wet Well Specification……………………………………..…16 Pumps Requirements…………………………………………..16 Pumps Specification………………………………………….…17

Unit Operations………………………………………………………….19 Primary Treatment …………………………..…………………19 Secondary Treatment………………………..…………………23

Executive Summary and Project Benefit………….….…………27 References………………………………………………………….………27 Appendix……………………………………………………………………28 Responsibilities……………………………………………………………40

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Overview

Letter of Intent

Go SAFe Water Management 2211 Lamar Drive Austin, TX 78701

May 13, 2016

Marfa City Council 113 S Highland Ave Marfa, TX Dear City Council,

The company addressing you is Go SAFe Water Management. We specialize in treating city wastewater. Our headquarters is based in Austin, Texas. The company has existed since 1990, and has had several projects throughout the country. We have built and designed treatment plants in very populous places, such as Phoenix, Arizona, Tampa, Florida, and even low populous areas such as Hershey, Pennsylvania and Red Oak, Texas. In the process of making all these projects happen, we were able to keep a cost effective solution for the operating costs and the initial costs. Our company has flourished with great minds with a love for water and environmental engineering. We have excelled in providing designs for water and wastewater treatment plants and would like to provide a proposal for the city of Marfa. The proposal is not for the present city as Marfa exist, but able to be operational for decades to come.

This proposal is for the benefit of the city and its people personally. Without a working wastewater treatment plant, a city’s production of clean water would stagger, so it would make sense to have the highest graded, optimal treatment plant to help a city and its people thrive. With our experience working with an arid climate, we understand how vital treated water is and how scarce it can be. Thank you for your time in reading this.

Sincerely, Office of Go SAFe Water Management Office of Go SAFe Water Management

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Company Background

Go SAFe Water Management has been in this challenging field combatting the various

difficulties wastewater present to the treatment plants, whether by helping with new designs or assisting in consultations to resolve an issue inside the wastewater plant. The company was founded in 1990 by a group of civil and environmental engineers who have the highest expertise in this field. Go SAFe Water Management is currently operating in the state of Texas with its strong technical efforts and well respected design. The company has been growing steadily in the present market as a solid technological and solution provider in the full spectrum of wastewater industry.

Reducing pollution to it is lowest required values by EPA in treating wastewater is our top priority. Furthermore, we consider in all of our proposed designs for wastewater plants to make a balance between the safety, quality, and total design cost. Go SAFe Water Management is a known team throughout areas of the United States for its affordable design costs and competitive quality.

(Picture of the Go SAFe Management, headquartered in Austin, Tx)

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Team Members

Head Engineers:

Zachary Ferguson

Zachary Ferguson was born and raised in Harrisburg, Pennsylvania. Late through his teenage years, he visited Pucallpa, Peru in order to help purify water for many settlements along the Amazon River. Zachary went to Texas Tech University for Chemical Engineering to specialize in the purification of water, but ultimately settled down at Lamar University for Civil Engineering in order to continue pursuing the cause of helping those that need clean drinking water, currently working at Go Safe Water Management. Zachary decided to create and organization with a fellow civil engineer, Diego Mingura.

Diego Mingura

Diego Mingura is from the Dallas area, specifically Sherman, Texas. Upon graduating Sherman High School in 2012, Diego chose Lamar University to further his education in Civil Engineering. Diego has worked 5 summer internships with the Texas Department of Transportation. At TxDot, he did concrete and asphalt paving, bridge construction, seal coat, and some surveying. During a trip to the Beaumont drinking water plant, Diego saw how important those types of plants were to society and how the engineers at the plant were so creative with cleaning the raw water. Diego then became intrigued in the drinking and wastewater treatment process. He decided to join Go Safe Water Management in order to further his knowledge of the drinking and wastewater plant design.

Design Engineers:

Sailee Gawande

Sailee Gawande was born in India and she has finished her under graduation in Power Engineering from “National Power Training Institute, India” and has a great experience of good 5 years in working at Power Plants as a senior engineer. Now that she has worked enough in an industry she wants to take care of the harm that industries do to the environment. So she pursued her masters in Environmental Engineering at “Lamar University, Beaumont, TX, USA” and now works as a Lead Design Engineer at Go Safe Water Management, working for treating the wastewater from the industries and the sewage water.

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Brandon Watkins

Brandon Watkins was born in Waco, Texas. After high school ended he switched from pursuing an architectural engineering degree to civil engineering because of his love for infrastructure, particularly bridges, but not too fond of illustrations. While in college, he visited a water and wastewater treatment plant, instantly amazed by how freely a civil engineer thinks from the environmental and water side. He applied for an internship at start of his Junior year at Go Safe Water Management. He has been employed by Go Safe for 8 years, where he is one of the Lead Design Engineers.

Supporting Engineer:

Ahmad Alzahrani

Ahmad Alzahrani was born and raised in Riyadh, Saudi Arabia; he went to one of its universities to accomplish a degree in civil engineering. However, he ended up taking it from Lamar University in Beaumont, Texas. He has been always dreaming of this valuable degree, which he thinks it is one of the most important fields of engineering because its contribution in helping improving communities and live matters. Eventually, he settled in Texas working for Go Safe Water Management since it was established.

Top (left to right) Zachary Ferguson, Diego Mingura Bottom (left to right) Ahmad Alzahrani Brandon Watkins Sailee Gawande

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Problem Statement and Project Objectives

Shown above (left to right) The abandoned oxidation ditch in Alpine, TX. (left) Overview of the facility (right) Close up of the brush aerator. Problem Statement

The city of Marfa is facing an urgent need to establish a new wastewater treatment plant. The EPA has placed constant pressure on the city to protect the underground water quality, in order to keep the city’s environment safe for residents and tourists. The growth of wastewater flow has made it difficult for the current wastewater plant to handle the treatment processes properly during tourism times, along with an inefficient treatment plant.

Project Objective

Go SAFe Water Management objectives are to design the new wastewater treatment plant while considering the following points:

- Estimating a flow rate of wastewater for the new generation of the local population of Marfa with this following population history:

Year 1950 1970 1990 2010

Population 2013 3605 4970 9100

- Providing an assessment of the characteristics of the raw wastewater. - Siting a strategic location that the wastewater plant will be located at. - Selecting a pump that can lift the wastewater from the wet well to the treatment plant. - Providing the layout of the new plant and the land area will be used. - Specifying the processes, sizes of the tanks, and the chemical will be used. - Considering the possibilities of any future needed expansion and the aesthetic features of the

plant.

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Design Flow Rate and Assessment of the Characteristics

Growth Population

The growth of the population of Marfa, Texas has been documented from 1950 to 2010 in integrals of 20 years. From the growth of the population, we were able to predict what the population will be in the year 2050. By plotting the growth in excel and using an exponential trend line, we were able to find the population of 2030 by using the function given for the exponential trend line. Using the updated function of the exponential trend line from the added integral year, we were able to calculate a predicted population in 2050.

Year 1950 1970 1990 2010 2030 2050

Population 2013 3605 4970 9100 12981 22189

Flow Rate

Considering the population speculation, we have decided for the designed flow rate of the plant to be 5 million gallons per day (MGD). After finding the population of 22,189 people, we multiplied that by 100 to find the Qdesign. This came out to be about 2.3 MGD. This would be the bare minimum designed flow rate. We had to account for vacationers and tourists that would venture into Marfa, TX. We could bump the designed flow rate to 3, but for fear of a water shortage or for it falling short, we can safely raise the designed flow rate to 5 MGD. This allowed for a nice cushion in case of an unexpected rise for treated water. Flow rate values were observed at minimum, average, and maximum flows. The ratio of the minimum hour on the minimum day was .28, whereas, the ratio of the peak hour flow at design capacity is 3.2. The ratios were multiplied by the designed flow rate. This gives a minimum flow rate at 5,299 m3/day and the maximum flow rate at 60,560 m3/day. The average was the designed flow rate of 18925 m3/day.

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Characteristics of Raw Wastewater

Municipal wastewater is mainly comprised of water (99.9%) together with relatively small concentrations of suspended and dissolved organic and inorganic solids. Among the organic substances present in sewage are carbohydrates, lignin, fats, soaps, synthetic detergents, proteins and their decomposition products, as well as various natural and synthetic organic chemicals from the process industries. The table shows the levels of the major constituents of strong, medium and weak domestic wastewater:

Constituents Concentration (mg/l) Total Solids 1200 700 350

Dissolved Solids 850 500 250 Suspended Solids 350 200 100

Nitrogen 85 40 20 Phosphorus 20 10 6

Chloride 100 50 30 Alkalinity 200 100 50 Grease 150 100 50 BOD5

2 300 200 100 Physical Characteristics of Raw Wastewater:

The physical characteristics of wastewater include those items that can be detected using the physical senses. They are temperature, color, odor, and solids. Temperature

Temperature of wastewater varies greatly, depending upon the type of operations being conducted at your installation. Temperature of sewage is slightly more than that of water, because of the presence of industrial sewage. The temperature changes when sewage becomes septic because of chemical process. The lower temperature indicates the entrance of groundwater into the sewage.

Color

Color of fresh sewage is yellowish grey to light brown. While that of the septic is black or dark due to oxidation of organic matter.

Odor

Smell of the fresh sewage is oily or soapy. H2S is the major source of pollution

Solids

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All matter except the water contained in liquid materials is classed as solid matter. The usual definition of solids, however refers to; “the matter that remain as residue upon evaporation and drying at 103 ± 20°C”.

The solids that are not dissolved in wastewater are called suspended solids. When suspended solids float, they are called floatable solids or scum. Those suspended solids that settle are called settle able solids, grit, or sludge.

All solids that burn or evaporate at 500°C to 600°C are called volatile solids. These solids serve as a food source for bacteria and other living forms in a wastewater treatment plant. Most organic solids in municipal waste originate from living plants or animals.

Those solids that do not burn or evaporate at 500°C to 600°C, but remain as a residue, are called fixed solids. Fixed solids are usually inorganic in nature and may be composed of grit, clay, salts, and metals.

Turbidity

The term “turbid” is applied to water/wastewater containing suspended matter or in which the visual depth is restricted.

Chemical Characteristics of Raw Wastewater:

Sewage contains both organic and inorganic chemicals in addition to various gases like H2S, CO2, CH4, and NH3 etc., that are formed due to the decomposition of sewage. The chemical characteristics of wastewater of special concern are pH, DO (dissolved oxygen), oxygen demand, nutrients, and toxic substances.

PH

PH is used to describe the acid or base properties of water solutions. The pH of sewage is initially high and drops when the sewage becomes septic but increases again with the treatment processes.

Dissolved oxygen (DO)

Wastewater that has DO is called aerobic or fresh. The solubility of oxygen in fresh water ranges from 14.6 mg/L at 0oC to about 07 mg/L at 35oC at 1.0 atm pressure

Oxygen Demand

It is the amount of oxygen used by bacteria and other wastewater organisms as they feed upon the organic solids in the wastewater.

BOD

BOD is defined as the amount of oxygen required by the bacteria while stabilizing decomposable organic matter under aerobic condition. It is written as by BOD or BOD5. “It is the

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amount of oxygen required by aerobic bacteria to decompose/stabilized the organic matter at a standard temperature of 20oC for a period of 5 days”. For domestic sewage 5 days BOD represents approx. 2/3 times of demand for complete decomposition. COD

By definition the COD is the amount of oxygen required to stabilized the organic matter chemically, i.e. the COD is used as a measure of the oxygen equivalent of the organic matter contents of a sample that is susceptible to oxidation by a strong chemical oxidant.

Nutrients

These are life-supporting. Nitrogen and phosphorus.

Toxic Chemicals

Most industrial use various types of toxic chemicals, the discharges of which can be harmful to wastewater treatment processes.

Biological Characteristics of Raw Wastewater:

However, pathogenic (disease-causing) organisms such as typhoid, dysentery, and other intestinal disorders may be present in wastewater. The bacteria in raw sewage may be expected to in the range from 500,000 to 5,000,000 per mL. These bacteria are responsible for the decomposition of complex compounds to stable compounds with the help of some extracellular and intracellular enzymes. Depending upon the mode of action of bacteria may be divided into the following three categories:

Aerobic Bacteria

Anaerobic Bacteria

Facultative Bacteria

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Wastewater Characteristics and Their Sources:

Physical characteristics-

Color Domestic/Industrial wastes, natural decay of organic matter

Odor Industrial wastes, decomposing wastewater

Solids Domestic/Industrial wastes, soil erosion, inflow etc.

Chemical characteristics-

Pesticides Agricultural runoff

Phenols Industrial waste

pH Industrial waste

Heavy metals Industrial waste

Toxic compounds Industrial waste

Biological Characteristics-

Biological Open water courses, treatment units.

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Layout and Land Area

Layout of the Plant

The plant is designed in a way where the land that will be purchased is as small as possible to handle all the treatment processes areas and to have free lands for future expansions. Furthermore, each treatment process was placed considering the easiness of reaching them. By referring to the graph, it can be seen that the wet well is placed in the first reached area from the city. Due to a continuous drop off and carry out from and to the sludge treatment and the chlorine storage, they are placed on the lanes around the treatment plant and close to the main road to make access easier to them. Also, the last process of the treatment is to be installed in the nearest area to the creek for an easier discharge in addition to the easy reach out to the chlorine storage.

(Layout of the treatment illustrated above)

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Land Area and Future Expansion

The land area will have to be suitable for future expansion. As of right now the Wastewater

treatment plant will be located at the 1421 elevation mark. The construction will take place west of US highway 67. The land area will be based upon the initial tanks being constructed. The areas of each tank plus how far apart they are from each other will also play a role in the actual land area that we will need to purchase, you also have to take into account for future expansion. Due to the areas of the tanks and how far apart they are from each other we decided that about 24280 m2 or 6 acres will be suitable for our final land area with considering any future expansion.

Preferred Location of the Treatment Plant

Location Requirements

The location of the wastewater treatment plant is a strategy that has to apply to the laws of gravity. In order for all of the wastewater to flow to the plant, the plant must be built on a lower elevation than every populated area in the city. This would allow the water to flow through the pipes and into the wet well in order to begin treatment.

Another factor that would come into play for the selection of the location would be and extended area for the treatment plant to have the option to expand in the future. This means that the location selected must have more room available than what our treatment plant is going to cover. It would also be necessary to note that the extended location does not include any mountainous terrain, for the treatment plant must be built on a relatively flat surface.

Proposed Location

Coordinates: Latitude X: 30.2930 Longitude Y: -104.0253 Height Z: 1421 meters (Top View of Marfa shown on the right)

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(Zoomed in view of the desired location to the right)

(Desired location of Wastewater Plant will be at 1421m of elevation as shown on left)

The proposed location was determined by finding out the lowest elevation outside of the city. The reason for that was to use gravity as our friend and let the wastewater naturally flow downward to the wastewater treatment plant. The location is very convenient considering there is a nearby creek. The creek will be the where the water that is cleaned from the wastewater plant will be discharged to.

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Pump Selection

Wet Well Specification

When designing the perimeter for the wet well, we had to take into consideration of the expected amount of wastewater that was flowing through it. We used the designed flow rate found before and multiplied it by the desired hydraulic retention time to find our desired volume of the wet well to be 9462.5 m3.

Since we want to design the wet well tank to be completely cubic, we can safely calculate the

length of each side to be 21.2 meters, and the area of each side to be 447.37 m2 After finding the dimensions of the wet well, we find the flow rate in m3/min in order to find the optimal pump and pump design for our wet well. The designed flow rate converts to 13.14m3/min.

Pumps Requirements

Using the flow rate for what is coming into the wet well, we need a pump system that would satisfy the conditions of preventing the overflow of wastewater in the wet well. By considering these conditions, a selected vertical non-clog centrifugal pump system was chosen. The pump design we chose was the 6WJFS Vertical Non -Clog Centrifugal Pump System.

The flow rate of the wet well was 13.42 m3/min and the maximum pump rate for the pump was 7.32 m3/min. Since we need more than one pump to satisfy the flow rate, we chose to add another section in parallel with the original pump, resulting in a flowrate of 14.68 m3/min, which exceeds the incoming flow rate.

For the Head of the wet well to be 21.2 m, our pump design would need to exceed 21.2 m. fortunately, the head of the pump happens to be 45.72 m, so we would not need to add another set of pumps in series. This would lead us to have a design of 2 pumps in parallel, with 1 pump in series. We add another pump in parallel in order to have a redundancy of 50% in case one pump experiences failure. The cost of the pump design will be $614.84 to operate each day.

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Pumps Specification

The 6WJFS Vertical Non -Clog Centrifugal Pump was the pump we decided to run with. The overall pump dimensions are 54 inches in length, and 22 inches in width and height. The suction inlet is 8 inches, and the discharge outlet is 6 inches. As for the features of the pump, it can handle a flow rate of 1934 gallons per minute, or 7.32 m3 per minute. The head that the pump can produce is 150 feet, or 45.72 meters. The pump rotates at a rate of 1780 rotations per minute. The weight of the pump is 1,225 pounds. It is used in industry for sewage and wastewater. These parameters all occur when it transports raw sewage at a temperature of 60oF.

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(Closer look at the desired vertical pump below)

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Unit Operations

Primary Treatment

Channel

To control flow and unsuspected maintenance, a dual channel is needed. To keep channel flow separate from each other, a slide gate (material being extruded aluminum) will be used when one channel is down. The channel material is concrete (roughness coefficient of .012). The channel invert is set 85 mm below the incoming sewer invert. The dimension of the channel is dependent and confined to approaching velocity value. The floor of the channel is slightly sloped downward in the direction of the screen to prevent solid waste buildup, however the channel is straight and perpendicular to screen. The channel width is calculated to be .87 m and length of roughly 8.5 m. Using Parshall Flume flow measurement, the depth of the channel is .85 m, with a freeboard is 1.45 m. Refer to 4. A Appendix.

(Picture of a dual channel above)

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Bar Screen

The bar screen chosen was the bar racks, designed for 5 MGD. This is most typically used in a wastewater treatment plant to filter out various debris. For the cleaning mechanism, a continuous belt was picked over a manual cleaning due lower maintenance and labor cost. The continuous belt is suited for trafficking solids, doesn’t jammed too easily, with maintenance taking place above operating floor. There are two bar racks placed in a dual channel, with the approach and through velocity are .4 m/s and .9 m/s respectively. The approaching velocity helps prevent the settlement of debris to be captured by the bar screen. The velocity through the screen regulates the overloading of solids coming to the screen. The area of the screen is .56 m 2. The material of the bar screen is stainless steel, though pricey, is corrosion resistant and sufficient maintenance. The bar design has a bar size width of 15 mm and bar size depth of 25 mm for mechanical cleaning method. The bar clear spacing is 25 mm, with a 20-degree slope from vertical. Calculations with the channel width and bar design gives screen having 24 bars. The effective area of the screen opening was configured to be .78 m2 . The head loss calculations were taken into account for peak hour flow rate. For a clean and partially clogged bar screen, the head loss values were .055 m (55.33 mm) and .047 m (47.38 mm), respectively. Head loss for partially clogged screen decides if it needs to be clean, limited to before 150 mm. For a 50% clogged screen, the head loss exceeds that at .224 (224.49 mm). Because the screen is mechanical, it will be time cleaned for 10 minutes and shut off for 20 minutes, implying the time cleaning cycle is 30 minutes. The frequency of cleans can increase due to increased flow. When screens need to be replace from the rake, they are place in a movable container. Refer to 5. A Appendix

(Bar screen for the plant above)

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Grit Chamber

The grit chamber that we chose was an aerated grit chamber. Being an aerated grit chamber, it allows wastewater to move through in a spiral pattern. Heavier grit particles settle at the bottom. Air is induced by air diffuser throughout the tank. There were a few parameters that we had to choose. These parameters included detention time, dimensions, baffles, air supply, velocities, and the quantity of grit. The detention time was 200 seconds. The dimensions were a width to depth ratio of 2:1 and the length to width ratio being 2.8:1. Those values gave us a volume of about 45 meters cubed. The area of the grit chamber was about 20 meters squared. Our baffles were longitudinal due to the fact of the placing. The placing was 1 meter from the wall. The air supply was found from the flow rate parameter in table 20.11. The value was .019 meters cubed per second. The velocity was determined by the baffle. Since the baffle selection was longitudinal the velocity value had to be a value that was across the bottom of the tank. That value was 0.4 meters per second. The last parameter was the quantity of the grit. That was in a volume unit and the value was 2.84 meters cubed. These parameters can be found in Appendix 6.A along with the calculations. The advantages and disadvantages of the aerated grit chamber are also mentioned in Appendix 6.A.

(Front view of a typical aerated grit chamber below)

(Diagram of aerated grit chamber shown above)

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Primary Clarifier

The primary clarifier is also known as the sedimentation process. It is the oldest and most widely used unit operation in the wastewater treatment process. The objective of the primary clarifier is to remove any scum or inert particulate matter that was not removed from the grit chamber. Some of the scum consists of grease, oil, plastic, leaves, rags, hair, and other floatable material. The parameters that are included in a primary clarifier are overflow rate, detention time, flow velocity, volume, surface area. Since we are designing circular tanks there is a feed well that is needed. The parameters for the feed well are detention time, volume, area, and the area of the pipe. Next is the splitter box. The splitter box should have a velocity of less than 0.02 meter cubed per second at peak flow. After follows the energy dissipating inlet. Those parameters are volume, surface area, and the weir loading. Many of these parameters were determined from the table in appendix 7.A along with the calculations. The values for designing the primary clarifier are as follows. Overflow rate was 38 meters cubed per meters squared day. The detention time was 1.7 hours. Flow velocity was 0.022 meters per second. The volume was 1369 meters cubed. For the surface area it was 326 meters squared. For the feed well the detention was 20 minutes with a volume of 263 meters cubed. The area of the feed well was 125 meters squared. The area of the cylinder through which the wastewater must flow is 83 meters cubed. The velocity through the area is 0.0026 meters per second. This value is substantially below the criteria of less than 0.3 meters per second. In that case we can increase the depth of the feed well to reduce the diameter. The volume for the energy dissipating inlet was 2.0133 meters cubed with a detention time of 9 seconds. The surface area is .96 meters squared with a diameter of 1.1 meters. The volume of the sludge hopper is 1.06 meters cubed. The last parameter is the weir loading rate. The weir loading rate was 287 meters cubed per meter day, which is within the customary range for weir loading rates. All of these parameters and calculations can be found in appendix 7.A.

(Primary Clarifier with a center feed above)

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Secondary Treatment

Aeration Tank

In designing the aeration tank, there were several parameters that we had to select. These parameters included the half velocity constant (Ks), the defined yield (Y), substrate utilization rate (k), maximum growth rate (μmax), initial BOD5 substrate concentration (So), BOD5 substrate concentration (S), endogenous rate of decay (Kd), hydraulic retention time (θ), recycle ratio (α), and biomass concentration MLSS (X).

Using these values, we can find the rest of our parameters using design calculations: Our growth rate constant (μ) = 1 1/day

Volume of the tank (V) = 4731.25 m3 Sludge age (θ) = 1.11 days

Observed yield (Yobs) = 0.54

Removal efficiency (R%) = 88%

Sludge production Px = 2248.29 kg/day

Oxygen Requirement (RO2) = 3424.846 kg/day

Food to Microbe ratio (F/M) = 0.4

Refer to appendix 9.A for equations

Secondary Clarifier From the aeration tank calculations, we were able to find out recycled flow rate Qr using the original flow rate and the recycle ratio. Recycled Flow rate (Qr) = 9462.5 m3/day Using the calculated Qr, we were able to compute the rest of the parameters for the secondary clarifier. Recycled Biomass concentration (Xr) = 6375 mg/l Flow Rate of the wasted water (Qw) = 1670 m3/day Exiting Flow Rate (Qe) = 17255 m3/day

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After finding those parameters, we select a designed Qoverflow = 500 gal/(ft2*day), or 0.8479 m/hr, so we were able to calculate the parameters to measure the Sludge Volume Index (SVI) Surface Area of the Secondary clarifier (A) = 1395 m2 Underflow rate Qunderflow = 6.783 m/day or 0.2826 m/hr Solid Flux = 2.12 kg/(m2*hr) After finding the overflow and underflow rates, along with the recycled biomass concentration, we plot the slopes and intersects on the Sludge Volume Index curve. From this, we can tell if there will be excess sludge build up. Refer to appendix 8.A for equations. The pump design for the recycled flow rate has to satisfy the conditions for Qr, which is 6.71 m3/min, and a Head of 20 m. fortunately, only 1 pump should suffice for these parameters. We will add an additional pump in parallel for a redundancy of 100% in case if the only pump experiences failure. The cost of this pump design will equate to $409.89 per day to operate.

(Diagrams of secondary clarifier viewed above and below)

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(Secondary clarifier shown above)

(Pump design for recycled flow rate shown on right)

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Tertiary Treatment For this part of the design, where nutrients (Phosphorus and Nitrogen) can be removed for

cleaner water without pathogens. chlorine can be used as a disinfectant for its effectiveness in the treatment, and its low cost. However, the chlorine needs to be removed before the treated wastewater is discharged to the creek. Therefore, aluminum sulfate can be added. The pH value should range between (5.5-7), and to keep it in range lime can be added to increase the alkalinity, which will increase the pH value, too. The concentrations of the chemicals can be figured out by doing a jar test of the Qe coming from the secondary clarifier. An Ideal Plug-Flow system can be used since it gives more hydraulic retention time which can help in producing a better water quality. With the required maximum time of 30 minutes, a bigger amount of pathogens can consume the maximum amount of the chlorine. From the calculated volume of 359.48 m3, the dimensions are supposed to be a length of 57.66 m, a height of 4.32 m, and a width of 1.44 m.

(Water in the tertiary treatment process above)

(A dual-media filters with a sand on right)

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Executive Summary and Project Benefit

A small recreation center are constructed for workers near the plant for enjoyment and relaxing for all day usage. Also, a garden is placed adjacent to the cafeteria for workers and visitors to welcomed, rather than an uncomfortable sight perceived at a typical wastewater plant. Working on this proposal allowed us to present to the client a cost-effective solution while meeting the water quality goals. With the area known for an arid climate, the project allowed us to think on how to make the treatment plant feasible and self-sufficient. Calculations for the various dimensions for the unit operation were done meticulously to ensure a top quality design. The flow rate design was determined above the actual to allocation for unforeseen circumstances.

References

Water and Wastewater Engineering: Design Principles and Practice, McKenzie Davis, McGraw-Hill, 2010.

Page of selected pump: http://www.smartturner.ca/non-clog-centrifugal-pump-system-sewage-wastewater-industry.html

Conversion Table http://powertrackhose.com/PDFs/ResourceLibrary/FlowratesUStometric.pdf

Site Location http://historicalmaps.arcgis.com/usgs/

Headquarters https://search.yahoo.com/yhs/search?hspart=ddc&hsimp=yhs-ddc_bd&p=office+building&type=bl-bfr-6YNKP__alt__ddc_dss_bd_com

SVI curve and State point analysis https://docs.google.com/uc?id=0BwTbFi_ZN3_nejVRZnJ6bTVRbzQ&export=download

Overview of a Typical Wastewater Treatment Plant https://www.como.gov/PublicWorks/Sewer/wwtppg_4.php

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Appendix A

1.A Population y=3E-17e.0235x=22,189 people by 2050

2.A Flow Rate Qdesign, actual=22,189*100=2.22 MGD=1541.7 GPM Qdesign=5 MGD=18925 m3/day The ratio of minimum hour to minimum day=.28 .28(18, 925) = 5299 m3/day The ratio of peak hour flow at design capacity=3.2 3.2(18, 925) = 60560 m3/day

3.A Pump and Wet well

Flow Rate (Q) = 1934 gpm = 10540m^3/day = 7.32m3/min Head loss (H) = 150 ft = 45.72 m Power (P) = 100 HP = 74.57 KW Chose a total of 2 pumps, plus 1 for redundancy Pumps will be running 24 hours per day Cost for Texas is 11.3 cents per KW*hr Cost for pump design = $.113*3pumps*24hr*74.57KW = $614.84 for pump design

4.A Channel

Aerial view of a channel

Front view of slide gate

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Parshall Flume

Dimension

W A B C D E F G mm

N mm

x mm

max flow

min flow n C

0.61 1.52 1.5 0.91 1.21 0.61 0.91 76 229 51 3360 1.56 2.6

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Depth of channel= (peak flow rate/C) ^(1/n) = (.7009 (m/s) / .91) ^ (1/1.56) = .85 m with freeboard= 1.45 m Channel width= clear width opening + (Bar width * No. of spacing)/1000 = .191 + (15 mm * 45) =.87 m Channel Length= Depth of Channel * 10= 8.46 m

5.A Bar Screen

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Clear area through= 0.248555 m^2 clear width opening= 0.191196 m 191.1964 mm No. of spacing= 45 space Headloss (clean)= 0.0553262 m 55.3262 mm Headloss (partially clogged)= 0.0473751 m 47.37513 mm Headloss (50% clogged)= 0.2244852 m 224.4852 mm No. of bars= 17 Bar Width= 15 mm V app.= 0.4 m/s Area= 0.559249409 m^2 6.01970471 ft^2 Vthrou.= 0.9 m/s

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6.A Grit Chamber Calculations: W=2.67m W:D=2:1, 2W=D D=5.33m L:W= 2.8:1, 2.8L=W L=7.5m V=2.36W3 Area=L*W=7.5m*2.67m=20.025m2 Air Supply= 0.00255 m3/(s*m)*7.5m=0.0191125 m3/s Quantity of Grit= .15m3/1000(m3) *18925 m3/day =2.839 m3

Table for Parameters:

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Advantages and Disadvantages

7.A Primary Clarifier

Calculations: Volume=1.7*3600*0.2237=1369 m3 Surface area= 1369/4.2=326 m2 Radius= (326/3.14).5=10.2 m Diameter =10.2*2=20.4 m (3-100m increments of 1.5) so use 21. Volume of feed well= (18925*20)/ (1440) = 263m3 Area of feed well= (263/4.2*.5) = 125m2 use 50% of depth.

Diameter= ((125*4)/ (3.14)).5=12.7m Area of cylinder= 3.14*12.7*(4.2-2.1) = 83m2 Velocity of water going through cylinder= (18925/ (83*86400)) =.002 m/s Volume of EDI=9*.2237=2.01 m3 Surface area of EDI= (2.01)/ (4.2*.5) =.957 m2, use half of feed well depth Diameter= ((.957*4)/ (3.14)).5=1.1 m

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For sludge hopper these were the parameters:

Bottom= 0.6m

Top=1.2m

Height= 1.2m

Angle of side wall= 75

Volume of sludge hopper= (1.2/3) *(1.2+.6+(1.2*.6).5) =1.1 m3

Weir loading rate= (18925)/ (3.14*21)) =287 m3/(d*m)

Parameters for primary clarifier:

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8.A Aeration Tank

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9.A Secondary Clarifier

Chose 1 pump, plus 1 for redundancy Cost for design = $.113*2pumps*24hr*74.57KW = $409.89 for pump design

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Daigger Method produced the following curve The SVI curve is 250

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10.A Tertiary Treatment

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Responsibilities

Engineer Responsibilities

Ahmad Alzahrani

Company Background, Problem Statement, Project Objectives, Layout and Land Area, Tertiary Treatment Design

Zachary Ferguson

Pump Design and Specifications., Aeration Tank Design, Secondary Clarifier Design, Wet Well Specifications, Population Predictions, Designed Flow Rate, Recurring Cost for Pumps, Location Requirement, Appendix, Letter of Intent

Sailee Gawande

Characteristics of Raw Wastewater, Population Predictions, Designed Flow Rate, Layout of the plant, Aeration Tank Design, Secondary Clarifier Design, Aesthetic Features of the Plant.

Diego Mingura

Location Requirement, Proposed Location, Grit Chamber Design, Primary Clarifier Design, Appendix Setup

Brandon Watkins

Pump Selection, Bar Screen Design, Channel Requirements, Population Predictions, Flow Rate Values, Appendix Setup, Letter of Intent, Editor