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SD&W Home City of Petal
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CITY OF PETAL |
| Size (inches) | Length (linear feet) |
|---|---|
| 2 | 101,500 |
| 6 | 152,200 |
| 8 | 70,540 |
| 10 | 8,550 |
The Mississippi Department of Health has established the following guidelines for minimum design criteria for community public water supplies. Also attached as Attachment 10 are the minimum flow requirements for the number of houses verses the required flow. The following guidelines were applied to the hydraulics in this report.
The distribution system is designed to maintain a minimum dynamic
pressure of 20 psi and a maximum static pressure of 80 psi. Higher pressures are considered on a case by case basis provided individual pressure reducers are used on the services.
All water mains are designed based on hydraulic analysis using an appropriate friction coefficient.
The following chart demonstrates the effect of a combination of two pipes installed in parallel.
| PIPE COMBINATION (inches) | EQUIVALENT SIZE (inches) |
|---|---|
| 2 - 2 ½ | 2.97 |
| 2 - 3 | 3.36 |
| 2 - 4 | 4.23 |
| 2 - 6 | 6.12 |
| 2 - 8 | 8.07 |
| 2 ½ - 3 | 3.61 |
| 2 ½ - 4 | 4.41 |
| 2 ½ - 6 | 6.22 |
| 2 ½ - 8 | 8.13 |
| 3 - 3 | 3.90 |
| 3 - 4 | 4.63 |
| 3 - 6 | 6.34 |
| 3 - 8 | 8.22 |
| 4 - 4 | 5.20 |
| 4 - 6 | 6.71 |
| 4 - 8 | 8.46 |
| 6 - 6 | 7.8 |
| 6 - 8 | 9.25 |
| 6 - 10 | 10.91 |
A computer PC-based program was used to determine the hydraulics of the existing and proposed improvements for the City of Petal. The Kentucky Woods or as currently recognized PIPE2000 Program was developed to calculate steady state flows and pressures for the pipe distribution system. The program can be applied to any liquid, but does not generally apply to gas flow unless the assumption of constant density is acceptable. The program is written to accommodate any piping configuration and various hydraulic components such as pumps, valves (including check valves and regulating valves), any component or fitting which produces significant head loss (such as elbows, orifices, etc.), flow meters and storage tanks. Computations can be carried out using both English and SI units.
Normal pipe network modeling involves the calculation of the flow in each pipe and the pressure at each node for a particular operating condition. In addition to carrying out these calculations, PIPE2000 has been enhanced to directly calculate a variety of additional design, operation and calibration parameters which will exactly meet stated pressure requirements. This powerful, state of the art capability, greatly increases the usefulness of PIPE2000 as a pipe network modeling tool by eliminating the trial and error procedure normally associated with such calculations.
PIPE2000 is based on solving the full set of mass continuity and energy equations utilizing efficient linearization schemes to handle non linear terms and a very powerful spare matrix routine developed by A. R. Curtis and J. K. Reid of the Theoretical Physics Division, UKAEA Research Group, Harwell, England. This approach accommodates elements such as closed lines, check valves, and regulating valves in a direct and very efficient manner. The approach also effectively handles data with widely varying parameter values. Extensive testing of various algorithms for pipe network analysis led to the conclusions that the approach used by PIPE2000 is the most powerful and has the best convergence characteristic of the commonly used approaches.
The city provides public convenience necessities for the residents of Petal. These necessities include water, sewer, sewer treatment and garbage disposal. The current water usage rates for the City of Petal are as follows:
| Gallons | Fee |
|---|---|
| 0-4,000 | $ 7.70 |
| 4,000-45,000 | $7.70 + $1.10 per 1,000 gallons |
A customer in the City of Petal using 14,500 gallons per month of water would pay a fee of $19.80.
Based on information provided by Wright, King and Associates, Certified Public Accountants, in the General Purpose Financial Statements for the year ended September 30, 2000, the following information is provided. The Water and Sewer Department received $728,825 for services rendered. Based on water usage rates stated previously in the report, the water department receives approximately 55% and the sewer department receives approximately 45%. The water department received approximately 55% of the total revenue collected by the water and sewer department or $400,853. Based on this criteria and using a current customer base of 3000, the average customer is metered approximately 200 gallons per day throughout the year. This is based only on the numerical average of the information provided. The consumption of a user will fluctuate throughout the year and also on a daily basis.
The financial status of the City of Petal previously detailed in this report reflected projected water usage based on income of the water and sewer department. During our preparation of our report, we discussed with Ralph Eddelman the water usage based on customer meter readings during the last year. The following metered flows are for the Year 2000:
| Month | Flow (gallons) | |
|---|---|---|
| Jan | 21,393,000 | 
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| Feb | 22,365,000 |
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| Mar | 20,586,000 |
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| Apr | 20,160,000 |
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| May | 25,135,000 |
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| June | 29,816,000 |
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| July | 28,199,000 |
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| Aug | 25,648,000 |
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| Sept | 25,869,000 |
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| Oct | 22,487,000 |
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| Nov | 23,686,000 |
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| Dec | 19,879,000 |
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| Total | 285,213,000 | gallons/year |
Using the metered amount of 285,213,000 and averaging over the course of a year (365 days per
year) results in an average usage of 781,405 gallons per day. By averaging this quantity
with 3,000 customers, results in an average of 260 gallons per day. This closely matches the
average of 200 gallons per day derived from the financial analysis section of this report. The
wells owned by the City of Petal are furnished with master meters. These meters register the total
amount of water pumped from the different aquifers. In the Year 2000, the master meters reflected a
total flow of 341,241,000 gallons. This indicates an unaccounted water consumption of 56,028,000
gallons of water or 16%. The unmetered water consumption equals approximately 153,000 gallons per
day. This water loss could result from leaks, flushing of lines, inaccurate meter readings, and
unmetered water users. The water loss results in additional operational cost without appropriate
reimbursements.
The City of Petal consumes approximately 1.5 million gallons of water on a peak usage day. The peak usage is in the high demand summer months when outdoor activities such as gardening, lawn watering, swimming pools, etc. are in high use.
The Mississippi Department of Health (MSDH) currently regulates the water quality for all public water supplies in the state. These regulations encompass many facets of water quality. The MSDH samples the water from different locations throughout the system at different times of the year. These samples are field tested or sent to Jackson to the MSDH Environmental Laboratory for analysis. From the information provided to Shows, Dearman & Waits, Inc. during preparation of this report, no adverse water quality samples have been present in the City of Petal water system. We have enclosed with this report a sample of the reports required by the MSDH. The enclosed reports are Physical and Chemical Water Analysis (P-Chem), Attachment 1. These reports show the well historical data and the analysis of the physical and chemical properties of the water directly from the well head. This sample indicates the type of water present in the underground aquifer and the type of treatment required prior to supply for domestic use.
A hydraulic analysis model was prepared for the current water system in the City of Petal. These hydraulics were based on the current information as supplied by this report. This report analyzes the domestic water usage, the fire flow potential and the age of the water. Each of these analyses are shown as attachments to this report. The attachments contain a map of the city reflecting the outcome of the analysis and the input and output. The fire flow hydraulic analysis was modeled adjusted to match the hydrant flows as determined by the Mississippi State Fire Rating Bureau. The bureau supplied information is contained in Attachment 5.
A summary of the results of the hydraulic analysis is below:
Domestic Use: The City of Petal currently is wholly within the guidelines as set forth by the Mississippi Department of Health (DOH). These guidelines state that while using a set demand as established by the DOH, all customers must possess a minimum of 20 psi of water pressure. All water lines within the City of Petal meet this criteria. Areas indicated in Attachment 3 reveal pressure between 20 and 35 psi in a few areas. The areas are Hyland Drive, intersection of Margaret Avenue and Griffith Drive, Old Corinth Road between Hillcrest Loop Road and Highway 42 and Vardaman Drive. These areas do not pose a concern for the system; however, if any unforeseen facility problems occur, these areas will experience low pressure problems first.
Fire Flow:
The City of Petal provides fire flow water [HYDRANT FIRE FLOWS]for all residents within the city limits. The guidelines for requirements are set forth by the Mississippi Fire Rating Bureau.
The guidelines state that the minimum flow required for all areas is 500 gallons per
minute. The enclosed map in Attachment 6 indicates the fire flows provided based
on the hydraulic analysis model. The map indicates pressures within the downtown
area in excess of 2,500 gallons per minute. A few areas on the model indicate areas
less than 500 gallons per minute and do not meet the guidelines set forth by the
Mississippi Fire Rating Bureau. These areas are generally located on dead end lines
and along the fringes of the City of Petal franchise limits. The computer model of
the hydraulic analysis generally matched the flow reported by the Mississippi Fire
Rating Bureau. A few hydrants were not within acceptable range.
Water Aging: Enclosed with this report is a set of data which reflects the aging of the water in the system. These calculations were run for a period of 3 days for the system to reach an equilibrium. The graphs show the age of water at 12:00 a.m., 8:00 a.m. and 4:00 p.m on the third day of the analysis. The graphs show the water aging in stages of 2, 6, 12, 24 and >24 hour periods. The maps indicate most water in the system is consumed prior to elapsing of 24 hours. Water on dead end lines located between the ground storage tank and the elevated storage tank are most susceptible to a water age over 24 hours. This water is not harmful for public consumption.
This report investigated the existing water infrastructure within the City of Petal. During the hydraulic analysis, the domestic flow, fire flow and water aging were investigated in great detail. The domestic flow and water aging parts of the investigation did not reveal any problems. The hydraulic analysis for fire flows indicated small problem areas. These areas
were primarily on dead end lines. The correction to repair these problem areas is to increase
the volume of water by installing parallel or looped water lines. The flow from the hydrants
which did not match the hydraulic analysis were probably from inadvertently closed valves.
All valves must be checked periodically to ensure proper operation. Also all valves must be
fully open to provide the proper volume of water flow.
The following recommendations are for upgrading the fire hydrant capacity to supply a minimum of 500 gallons per minute at 20 psi at the previous fire hydrant:
This water plant is
located on Hillcrest Loop Road approximately one half mile north of Carterville Road at the
intersection of Hillcrest Loop Road and Boxtel Street. The plant site consists of a water well,
aeration tower, chlorination and pH adjustment, detention basin and service pumps. The site is
protected by a security fence along all sides. The well is located adjacent to the aeration basin
and was constructed in 1962. The depth of the well is134 feet and is located in the Alluvium
Aquifer. The well head pump produces in excess of 700 gallons per minute of water flow. This water
is transferred to the aeration stack to remove carbon dioxide (CO2) from the water.
After the aeration treatment, the water is combined with chlorine gas and lime and placed in a
15,000 gallon holding reservoir. The lime is added to the system to raise the alkalinity to an
acceptable level. The chlorine is added to the water to prevent microbiological growth in the water
of the reservoir and the distribution lines. The reservoir is an underground concrete structure
with a maintenance building located directly on the roof. The reservoir is filled with treated
water and stored until needed in the system. When needed, a service pump supplies water to the
system. Two 500 gallon per minute service pumps are present at the reservoir and alternate between
each for pumping.
This water plant is
located on South Main Street approximately 500 feet south of Central Avenue and adjacent to the
Rite Aid Store. The plant site consists of a water well, aeration tower, chorination and pH
adjustment, detention basin and service pumps. The site is also protected by a security fence along
all sides. The well is located northwest of the existing treatment plant and was constructed in
1988. The depth of the well is 87 feet and is located in the Citronelle Aquifer. The well head pump
produces in excess of 500 gallons per minute of water flow. This water is transferred to the
aeration stack to remove carbon dioxide CO2 from the water. After leaving the aeration
treatment, the water is combined with chlorine gas and lime and placed in a 15,000 gallon holding
reservoir. The lime is added to the system to raise the alkalinity to an acceptable level. The
chlorine is added to the water to prevent microbiological growth in the water of the reservoir and
the distribution lines. The reservoir is an underground concrete structure with a maintenance
building located directly on the roof. The reservoir is filled with treated water and stored until
needed in the system. When needed, a service pump supplies water to the system. Two 500 gallon per
minute service pumps are present at the reservoir and alternate between each for pumping.
This water plant is
located on Old Richton Road in the southeast corner of the intersection with Kelly Rose Lane. This
plant works in conjunction with an elevated storage tank. The plant site consists of two water
wells, chlorination and phosphate adjustment and the elevated storage tank.
This ground storage tank is
located on the east side of Fairchild Drive approximately 300 feet south of its intersection with
Old Richton Road. The storage tank is supplied with water from treatment Plant A and Plant B as
previously identified. The capacity of the tank is 500,000 gallons, and the dimensions are 75 feet
high and 34 feet in diameter. The flowing gradient of the tank is 341.0 feet above mean sea
level.