CIVE322REPORT

CIVE 322 – Environmental Engineering Water Treatment Plant Field Trip Report Department of Civil Engineering University of Louisiana at Lafayette May 1, 2020 Prepared by: Fahad Bux_________________________________________________________________________ Garrett Menard_____________________________________________________________________ Moahmmed Al Balushi_______________________________________________________________ Shay Broussard_____________________________________________________________________ Tanner Shaddox_____________________________________________________________________ Seth Benoit_________________________________________________________________________ Submitted to: Dr. Daniel Gang

TABLE OF CONTENTS I. Introduction……………………………………….……..………………… ........................................... 5 II. Raw Water Characteristics…….……………………………………………… ..................................... 8 III. Process, Configuration, and Layout ………………………………………… ...................................... 9 IV. Finished Water Quality ……………….. ............................................................................................. 14 V. Discussion ............................................................................................................................................. 15 VI. References……………………………………………………………………… ................................ 16 2

LIST OF TABLES Table 1: Raw Water Characteristics...….………………………...…………… ......................................... 8 Table 2: Flow Capacities/Dimensions …………...…………….………….…… ...................................... 11 Table 3: Chemical Usage..…………….………………… .... …………………………………………….11 Table 4: Power Input…………………………………………………………………………... ………...12 Table 5: Finished Water Quality Characteristics .... …..……… .... ………………………………………..14 4

I. Introduction and Background Life is linked to water, it is just another definition for life. On earth, there would be no existence of life without water, it’s the most essential and valuable resource. Approximately the water covers 71% of earth’s surface, 97.4% of water is found in the ocean, the other 2.6% is freshwater that is founded in ice caps, and groundwater with a percentage of 1.98% and 0.59% respectively. There are many major pollution sources that could affect the water on the earth and make it harmful such as pathogens, nutrients, synthetic organic, oxygen demanding wastes, etc. Therefore, extracting clear healthy water is an issue that needs to be addressed. Our whole human civilization was built on the use of water. Throughout history, civilization had faced challenges to produce clear drinking water. In the past, the water was examined to make sure it is safe and drinkable by looking at how clear the water is and if its taste had changed. In ancient Egypt, finding water wasn’t easy to find. For most Egyptians, the river Nil was the only source of drinking water. People would wash themselves, wash their bodies and clean their clothes in the Nil. The bacteria in the water was causing people to feel ill. As a solution, chemicals such as alum were added; it acts as a magnum to remove any harmful bacteria from the water. However, the problem was still not solved. During the period of Greeks, Hippocrates (the father of medicine) studied how dirty water affected people’s health. He developed a way by using a cloth to strain water through capturing any water before boiling it. In the early mid 1600s, Francis Bacon discovered a fundamental part of purifying water by using a method called sand filtration. This method has straightened the path for clearer purified water. Additionally, a Dutch scientist Antonio Leeuwenhoek in 1674 observed the first bacteria using the microscope on water. This discovery was the first step that helped produce the method of water treatment that we know of today. Nowadays, water goes through a series of steps and processes before it is filtered and made safe to use. After the water is collected from its main source, it flows from the intake point (river, lake, etc…), then goes through a treatment plant, to a storage tank that then distributes the water to our houses through various pipe systems. The community being aware of healthy drinking water established an Environmental protection agency (EPA) in 1970. Setting standards and regulation to protect the public health. Primary standards which are legally enforceable standards that apply to public water systems to protect the public health by limiting the level of contaminants in drinking water. Secondary standards are the non-enforceable guidelines regulating contaminants that may cause cosmetic or aesthetic effects in drinking water. one notable standard of water that should be met is that the mercury concentration should not exceed 0.002mg/l. 5

The LUS south water treatment plant field trip has taught us the process that water undergoes to provide safe and aesthetically pleasing water. A journey of raw water going through chemicals, entering the settling tank, getting filtered then gets disinfectant and reaches our homes purified and clarified. It shows how fortunate we are to have access to healthy water more than any time in history. 7

II. Raw Water Characteristics The first step in the water treatment process begins with collecting raw water from the Chicot Aquifer beneath southwestern Louisiana and even parts of Texas. The Chicot Aquifer is the main source of raw water for most of the areas that lie above it. LUS currently has nine wells placed above the Chicot Aquifer within Lafayette. On an average day, each well will pump approx. 10 million gallons of water per day. Of all the areas utilizing the Chicot aquifer, Lafayette consumes the most raw water from the Chicot. Notable levels of manganese and iron can be seen in the water pumped from the aquifer. As can be seen from the table below, the levels are quite high and must be treated to reduce hardness in the water. This hardness in the water will cause the water to leave behind water spots and scale which can be harmful to water systems and leave buildup on faucets. One of the main goals of the plant is to provide not only safe drinking water but also visually and physically clean and soft water. The LUS plant can lower the hardness by adding lime and aluminum sulfate to the coagulation and flocculation processes. To sum this section up, the raw water pumped from the Chicot aquifer is generally very usable, yet still needs to undergo the treatment process to provide a safe drinking water product. Raw Water Characteristics Characteristic Value / Range pH 7.5 Hardness 150 mg/L Iron Content 0 mg/L Manganese Content 0.11 mg/L Table 1: Raw Water Characteristics 8

After the addition of phosphate, the water goes through filtration tanks. Only one filter is used at any given time to reduce the strain on them. Each filter consists of anthracite coal, sand, and gravel which work to remove the rest of the finer particles not taken out in the clarifiers. The filters each filter at a rate of 3.5 gal/min/ft². Every 70 hours, the filter is cleaned by backwashing, a 20 to 30-minute process in which water is pumped back through the filter to the settling tanks to remove built-up sludge on the filters. The settling tanks are tall cylindrical structures with conical bottoms (not visible from the outside) where sludge settles and exits to the thickener tanks. In the thickener tanks, the settled sludge, which contains beneficial nutrients for grass, is removed and sent to farmlands. They have a deposit for a truck to drive up to the plant and collect the sludge to be used on farmland as you can see in the picture below. Figure 4. Sand Filtration Control Panel Figure 5. Backwash Settling Tank After the water has been filtered through the regular process, it is pumped into storage in one of the clearwells. Within the clearwells, the water is further disinfected with chlorine in “post-chlorination” to make it suitable for public consumption. The clean water is then pumped out of the system for public use. Due to the fluctuation of usage rates throughout any 24-hour span, ground storage tanks are employed to hold extra clean water when usage rates are low, for example at night. The treatment process at the LUS water treatment plant goes through many stages to convert the Chicot Aquifer water to safe, drinkable water for the South Lafayette Parish area. The overall process of the plant is outlined in figure __, and the plant’s layout is illustrated in figure __. 10

TABLE 2. Flow Capacities/Dimensions Major Unit Quanity Flow Capacity (gal/min/ft^2 ) Dimensions LxWxH (ft) Dimensions DxH (ft) Volume (ft^3) Detention Time (min) Treatment Unit #1 1 - - 68x15 54475.2 45 Treatment Unit #2 & 3 2 - - 76x16 72583.3 2x 45 Filters 8 3.5 8x 27x15x12 - 4860 8x - Thickeners #1 & 2 2 - - 36x14 14250.2 2x - Lime Bins #1-4 4 - - 12x18 2035.7 4x - Backwash Settling Tank 1 - - (top) 26x33 (cone) 26x11 to 8 D 17520.6 1946.7 45 Table 3. Chemical Usage Chemical Application Rate (ppm) Point of addition Method of addition Purpose Chlorine 3 Pre and Post Treatment Automated with rates checked periodically Disinfectant Lime 100 Clarifier Inner Ring Automated with rates checked periodically Water Softener Alum 1 Clarifier Inner Ring Automated with rates checked periodically Flocculent Phosphate 1 Clarifier Output Automated with rates checked periodically Corrosion Control 11

KEY 1:1 Scale 13

IV. Finished Water Quality Characteristics Finished Water Quality Characteristics Characteristics Value/Range Maximum Contaminant Levels (MCLs) pH 8.3-8.4 6.5-8.5 Hardness 96-116 mg/L 500 mg/L Iron Content 0 mg/L 0.3 mg/L Manganese Content 0 mg/L 0.05 mg/L Table 5: Finished Water Quality Characteristics For human to survive, we need to maintain an intake of drinking water that is not only reliable but also uncontaminated. In response to this, the United States established the Environmental Protection Agency (EPA) on December 2 nd , 1970, which ensured primary and secondary standards for the processed drinking water we acquire every day. These standards, made by the EPA, were set forth to ensure that all providers maintain a quality of drinking water that is beneficial for our entire population. The primary standards from the EPA are a set of mandatory standards which limit the maximum contaminant levels found in drinking water, which if surpassed result in consequences for the provider. However, the secondary standards from the EPA are optional standards that regulate the contaminants in the drinking water to ensure that the processed water is aesthetically pleasing, which includes the color of the water and its fluidity. As shown above in Table 5, the Environmental Protection Agency standards are followed and enforced in the Lafayette Utility System South drinking water plant. In order to start the process of removing the iron and manganese from the raw water, chlorine is added into the system so that the unwanted substances are oxidized. Once this is done, lime and aluminum sulfate are added to assist as coagulants for the water during flocculation. The combination of these chemicals and the ongoing treatment process allows for the iron and manganese to dissipate almost entirely from the raw water. As a result, the pH of the water rises from its natural pH of 7.5 to a pH ranging from 8.3-8.4. Once the iron and manganese are removed from the water, its hardness drops to around 106 mg/L, which helps prevent damaging of the pipes and other systems found within the LUS South drinking water plant. 14

V. Discussion Lafayette Utility System (LUS) goal is to provide safe and pleasing drinking water to the Lafayette parish area since 1980. LUS has a reliable water treatment plant that has great credentials backing them up to provide to safe drinking water to the city. The plant produces closes to about 9-10 million gallons of drinking water per day. The water treatment plant provides some of the highest drinking water quality, surpassing regulations. The first investigation was conducted in 1991, and ever since then LUS has no record of line in its water distribution containing lead or any type of violation in that matter. LUS has a built a very credible reputation since being established. The treatment plant is mostly operated through computers and carefully supervised by the workers. About 90-95% is computerized work, there is always 2 operators per shift. The computer processing system that runs the plant is one of the most advanced in the state, using fiber optic security control and data acquisition system. This system allows for the processes and necessary information to be available on and off site. It can display many information such as changes in chlorine levels, amount of water intake in gallons per minute, contamination levels, etc. The design values for the treatment process have parameters that control their respective efficiencies and input/output rates, such as the detention time have been deemed to be adequate based on the values of finished water quality based in the book. The detention time is 40-45 minutes. Running the LUS plant it takes nine high service wells, that range from about 100-200 HP. For the clearwells and storage, there is four clearwells and two storages that have a total of 5.145 MG. When it comes to personnel cost, such as salaries for the employees and insurance/tax it comes out to 1.7 million dollars. As for non-personnel costs which comes out to roughly 3.4 million dollars, most of that chunk comes from the power service and chemical treatment supplies. For the chemical treatment supplies, lime is the most expensive one because of regulating the waters pH. There is no weakness to the plant other than mostly weather conditions, for example if the water were to be frozen from it being cold. But that’s not an issue in Louisiana since we’re in a subtropical area. As of right now there are no plans upgrade/expand the plant, which makes sense since there aren’t ever really any problems. LUS has shown to be reliable and adequate based on their results. 16

VI. References "THE HISTORY OF CLEAN DRINKING WATER." The History of Clean Drinking Water | APEC Water. N.p., n.d. Web. 23 Apr. 2020. Masters, G. and Ela, W. (2008). Introduction to Environmental Engineering and Science . Upper Saddle River, NJ: Prentice Hall. 17