In this article we will discuss about the treated sewage effluent for landscape irrigation.
Fayez Al-Mathkour
The Public Authority Agriculture Affairs and Fisheries Resources, Department of Execution and Maintenance of Greenery—Beautification Projects, Rabiya
Abstract:
The Ministry of Public Works (MPW) and Public Authority for Agriculture Affairs and Fisheries (PAAF) have been studying to utilize the Treated Sewage Effluent (TSE) for the whole state of Kuwait Greenery and Landscape Projects.
The TSE projects has been divided into three phases with a total TSE water requirement of 60 million gallons/day for the whole Kuwait Master Plan for treated sewage effluent (TSE). Phase 1 project is under contract No. SE/S/135 between MPW and Mushrif Trading and Contracting Company which began on September 10, 1994.
This contract is to design, construct, operate and maintain the tertiary treated sewage effluent facilities with a total water demand of 5.1 million gallons/days and design and prepare tender documents for facilities under as project (B1/B2) with a total water requirement of 23 million gallons/ day. The described total water demand for phase 1 project of TSE from Riqqa and Ardiya throughout design period until the year 2020.
The area for Phase -11 to be served by Riqqa and UMM Al-Hymann with a total TSE estimated water requirement of 11.43 millions gallons/day to be served under phase – II.
The usage for TSE is to irrigate the landscaped and beatification projects within and around Kuwait City in particular for highway site, major roads and internal roads. The type of irrigation system to be used mostly will be drip system.
Introduction:
The Ministry of Public Works (MPW) and Public Authority for Agricultural Affairs and Fisheries Resources (PAAFR) have been studying the utilization of the treated sewage effluent (TSE) for greenery and landscape projects throughout the State of Kuwait. The TSE project has been divided into three phases with a total TSE water requirement of 60 million gallons/day (mgd) for the Kuwait Master plan.
Phase 1 of the project is provided under contract no. SE/S/135 between the MPW and the Mushrif Trading and Contracting Company. It commenced on September 10, 1994. This contract is for the design, construction, operation and maintenance of tertiary TSE facilities with a total water demand of 5.1 mgd, and the design and preparation of tender documents for facilities under project B-l/B-2, with a total water requirement of 23 mgd.
The described total water demand is for phase I of the TSE project from Riqqa and Ardiya throughout design the period until the year 2020. Upon the MPW’s and PAAFR’s review of the TSE Master Plan, the area of Phase II is to be served by Riqqa and future waste water Treatment Plants (WWTPs) in Shuaiba and Umm Al-Hymann with a total TSE estimated water requirement of 11.43 mgd.
The area of Phase III is to be served by the Ardiya and Jahra WWTPs with an estimated water requirement of 28.58 mgd. The Kuwait Master Plan’s projects will be monitored and controlled from one station through a telemetry and satellite control system. All TSE will be used to irrigate the landscape and for beautification projects within and around Kuwait City, in particular for the road sides of highways, major roads and internal roads.
The type of irrigation system to be used most often will be the drip system. The State of Kuwait’s water resources are limited, and no plants can grow without irrigation. Rainfall, which amounts to an annual average of 120 mm, is inadequate to support any kind of plantation or rained agriculture.
The PAAFR is the main government body entrusted with implementing the desire of HH the Emir to green Kuwait City. The PAAFR is cooperating with other governmental bodies, such as the MPW, the Ministry of Electricity and Water (MEW), and Kuwait Institute for Scientific Research (KISR), to carry out the greenery plans of the state.
Brackish groundwater is the main source of irrigation for landscaped areas. Freshwater is also available through tankers. TSE has not been extensively used in the past due to the lack of a proper distribution network and facilities. Special projects and studies have been initiated (Phase I) in cooperation with the MPW, MEW and PAAFR to expand TSE usage. Such projects are in the implementation stage, and studies are continuing for Phase II.
The PAAFR’s activities can be summarized as follows:
1. Utilization of the TSE in cooperation with the MPW and MEW for landscape irrigation.
2. Preparation and checking of the irrigation designs for the road side areas along motorways and main roads and for public gardens and other governmental areas.
3. Preparation of standards and specifications to be followed during the installation of irrigation systems.
4. Supervision of the installation of irrigation systems.
5. Training of staff and preparation of technical material.
Activities and Work Status:
Since the beginning of this project PAAFR in cooperation with the MPW and MEW has prepared study and tender documents for Phase I.
Phase 1 includes the following:
Part I Study and Design:
1. Investigation, study, evaluation and preliminary design for Phase I
2. Detailed design of the urgent Project A (VIP) route
3. Detailed design and preparation of tender documents for the area ‘B’.
Part II Construction:
Construction, installation, testing and commissioning of the system’s facilities and equipment of the Area ‘A’.
Part III Operation and Maintenance:
Operation and maintenance of all executed work under urgent Project ‘A’. The tender for the implementation of Project Area ‘A’ was started in early 1994, and was awarded to the Mushrif Trading and Contracting Company in August 1994. Part I of Phase I of the Area TSE Project is almost complete.
The consultants have submitted detailed designs of project ‘A’ and after modification including a variation their order they have been jointly approved by the PAAFR and MPW. The PAAFR has requested that supply of water from the Ardiya WWTP, which is closer to the project area and more reliable source of water than Riqqa WWTP.
Part II includes the construction of the transfer main, storage reservoirs, pumping units and other equipment under the urgent Project A (VIP route). Works has been started with some delays due to the difficulties in obtaining the municipalities agreement as to the location of the reservoirs. Work is going on, and it is expected to be completed by the middle of 1997.
The tender documents under Phase I cover only the transferring and storage of TSE in various reservoirs within the project areas. The distribution of water, i.e., the irrigation network from the reservoirs to the landscaped areas, is not included. This task was handled by the PAAFR through on-going contracts for the maintenance of landscaped areas.
In parallel to the TSE project, the PAAFR has started preparing designs for the irrigation distribution network beyond the reservoirs, and has begun to execute these through maintenance contractors. This activity is on-going, and by the middle of 1997, when the transferring and storage of the TSE project is completed, the irrigation network will also be ready. Already 90 per cent of this network has been completed and is functioning with brackish water or through injection of freshwater.
Treated Sewage Effluent Utilization (TSE):
Main Elements of the TSE under Phase I:
Project Area:
The area to receive water is the main area of Kuwait City from 6th Ring Road to Gulf Road and the Ghazali Expressway.
This area has been divided into three subareas for financing and construction purposes:
1. Project A:
The VIP route which includes the King Faisal Motorway (from the airport to 5th Ring Road (from Airport Road to Fahaheel Road) and Khatabi Street.
2. Project B1:
The covered area lying between King Faisal Road, 6th Ring Road and Gulf Road from the Flag Area to Messilah, excluding 5th Ring Road and Khatabi Street, which will receive water from Project A.
3. Project B2:
The area covered by this project lies between the Ghazali Expressway in the west and King Faisal and Riyadh Street on east. Gulf Road (from the Ghazali Expressway to the Flag Area) on the north and 6th Ring Road on the south (about 1 km south of 6th Ring Road).
The Main Elements of this TSE design system are shown in Table 1:
Status of Works (as of September 1996):
Project A (VIP route) is being implemented and is expected to be completed by the middle of 1997. The cost of this project is KD 4 million the design detailed drawings and all tender documents for Project B1 and B2 have been completed.
Source of Water:
The Riqqa Treatment plant is the main source by using the existing 1200 mm line passing along the 6th Ring Road to Ardiya and in Sulaibiya Data Monitor Center (DMC). Three tapping points on that line will provide water to the three projects.
It is anticipated that in the future there will be a shortage, and the Ardiya plant will have to supplement the deficit. Although Riqqa is capable of producing about 14.6 mgd at present, its production will be almost doubled in the future. However, there is a constraint on supplying the water.
Water from the Riqqa WWTP, due to the limitations of the existing 1200 – mm line, has a rate of delivery of only 946,00 gal/h (4300 mVh) and even full utilization of this rate for a 24 period requires storage facilities since irrigation is limited to only 12 h/d. It has been estimated that the maximum quantity of effluent which could be used from Riqqa for Phase I of the project is 19.3 mgd (Tables 2 and 3).
Production of the Riqqa WWTP will double in the future. However, Phase I to the project (A+B1+B2) requires 28 mgd although it cannot use more than 19.3 mgd from this station due to the carrying capacity of the mainline of 1200 mm diameter and the shortage of reservoir capacity in the Phase I project area.
Points of Concerns for the PAAF Related to the Design:
1. The Riqqa line of 1200-mm has limited flow capacity for meeting the project’s water demand, i.e.,
a. Flow from the Riqqa line 4,300 m3/h
b. Maximum flow demand to meet the peak water demand at full development within 12 hours is 10,640 m3/h
c. The Maximum quantity of water which could be used from Riqqa WWTP plant for Phase 1 19.3 mgd compared to the total water demand, which is 28.1 mgd;
2. The capacity of the three main reservoirs for the three projects A, B1 and B2, is small, i.e., 500,000 gal/reservoir;
3. The capacity of most of the reservoirs is 176,000 gal (800 m3), which is considered small and will cause operational problems considering the supply rate and the irrigation pumps requirements. The reservoir storage capacity is about 25 per cent of the daily water demand. The total storage capacity is 7.98 million gallons compared to the total daily demand of 28.1 million gallons.
Project A (The VIP Route):
Areas:
Project A includes the VIP route, i.e., the King Faisal Motorway (from the airport to 5th Ring Road), 5th Ring Road (from Airport Road to Fahaheel) and the Khatabi Street. Approximately of 12 km will receive TSE by May 1997.
In addition, Project A will supply water to 4th Ring Road and all sections of expressways as well as internal roads included between 4th Ring Road, 5th Ring Road, Airport Road and the Fahaheel Expressway.
Water Demand:
It is estimated that the distribution network will be able to supply 5,138,066 gpd (23, 180 m3/h. The system has been designed to yield is quantity 12 of operation.
Main Activities:
The main activities under the Project A are as follows:
1. Delivery of water from the existing 1200-mm-diameter Riqqa line to a storage reservoir near the airport by gravity.
2. Construction of six reservoirs including a main reservoir which will be located next to the Riqqa main line; one reservoir, the R-35 (near the 4th Ring Road and Demascus intersection) will be constructed at a later stage under Project B1.
3. Upgrade four existing reservoirs with their pumping unit located along the VIP route.
4. Construct transfer main lines from the reservoir (near the airport) to all new and existing reservoirs.
5. Install irrigation pumping units at all new reservoirs.
6. Install a satellite irrigation control and telemetry system.
The irrigation network has already been completed and is in operation using brackish freshwater. Upon completion of the work of Project A, the brackish and freshwater will be disconnected, and TSE will be used.
Reservoirs in Project A:
Detailed information on the reservoirs to be utilized in Project A is provided in Table 4.
Irrigation Pumping Units in Project A:
Each reservoir, including the main one (R- 22), will have one or two sets of irrigation pumping units to convey water under pressure to the irrigation network. In each set of irrigation pumps, there will be three main pumps (two duty pumps and one standby), and one jockey. The pumping head is 60 m meter in all pumps.
The R-35, which will constructed at a later stage under project Bl, will be fed from project A and will have two sets of 60-60-60-60. In this case, three pumps will be duty pumps and the fourth will be standby. There is no jockey pump since all pumping units within Project B will have variable frequency speed control relays. Already all the existing pumping units in the motorways project have this variable speed control system on an experimental basis.
Table 5 Contains details on the capacity of the pumps that will be used:
In the future i.e., within 6-10 years this pumping capacity will not be sufficient and additional irrigation pumps will have to be installed, or to be replaced with bigger pumps. The ultimate future irrigation pumping capacity required is 1,946 m’/h in order to supply the potential daily water demand of 5,138,066 gpd (23,358 m3/d) within the 12-h daily operation of the irrigation system.
Transfer Pumps in the Main Reservoir (R-22) of Project A:
There will be three transfer pumps at the R-22 (near the airport) reservoir, i.e., two duty pump and one standby, to pump water from R-22 to the other reservoirs. The pumps capacity is 2201/s with a 40-m head for each pump, i.e., there will be a 440-1/s total pumping capacity (which can exceed 500 1/s).
Transfer Lines in Project A:
Approximately 18 km of transfer line with various pipe diameters will be installed. The pipes are ductile iron except the first portion which carries water under gravity and is connected to the 1200-mm Riqqa line within the R-22 reservoir. This line, although initially 800 mm, the actual constructed of 1000-mm concrete pipes. The rest of the pipes, under this project will be under pressure line, vary from 600 mm to 250 mm in diameter.
Satellite Irrigation Control and Telemetry:
A satellite irrigation control and telemetry system will be integrated to provide more efficient operation and use of TSE for the whole of project area. The project will have a unique telemetry and satellite system to fully monitor and control the reservoirs and the irrigation network.
This system is being implemented for the first time in the State of Kuwait. The system uses Supervisory Control and Data Acquisition (SCADA). The SCADA interface will be installed at Reservoir R-25, which will be the Master Control Station.
The Master Control Station will be able to monitor the status of and control devices like pumps and valves without any need for Personnel interaction. The SCADA remote terminal units (RTUs) and field control units (FCUs) will control the total irrigation on the basis of various variable parameters like temperature and humidity and moisture. The utilization of water will be optimum since only the amount of water will be allowed to flow through the irrigation valves.
The main components of the telemetry and satellite irrigation control system:
1. The main control office at R-25 where all the data and information will be collected in a central computer system with a display unit. All data will be transmitted via radio signals of 376 MHz. Proper software will be the main element for controlling and monitoring the irrigation system.
2. RTUs, which will be installed near the reservoirs (one for each reservoir). The RTU will monitor the reservoir’s water level, inflow, pump status, water pressure to the irrigation system, alarms, etc. All information will be sent to main control office via radio signals.
3. FCUs, which will be installed within the irrigation network and connected to the remote control valves through low-voltage wires. The FCUs take the place of the existing irrigation controllers and will be receiving ON/OFF signals through the RTUs from the main control office.
4. A weather station. All commands for irrigation scheduling will be given to the system through the computer in the main office. The weather station will interact automatically to change the irrigation schedule when rainfall occurs. Any failure in the system will appear on the display, and alarms will indicate where the failure has occurred.
Project B1:
Area Covered:
The covered area is lies between King Faisal-Riyadh Street, 6th Ring Road and Gulf Road from the Flag Area to Messilah, excluding 5th Ring Road and Khatabi Street, which will receive water from Project A.
Water Demand:
The peak daily irrigation water demand is 17,869,000 gpd (82,221 m3/d).
Main Activities:
The main activities under Project B1 are as follows:
1. Delivery of water from the existing 1200-rnm-diameter Riqqa line to the R-11 storage reservoir by gravity,
2. Construction of 21 new reservoirs including the main one (R-11) which will be located next to the Riqqa main line; One of those reservoirs, the R-35, will be used to supply water to Project A.
3. Upgrade five existing reservoirs and their pumping units (PH-1, PH-5, PH-6, PH-7 and R-10),
4. Construct transfer main lines from the mainline reservoir (R-11) to all new and existing reservoirs, over a distance of approximately 67 km with diameter varying from 250 mm to 1000,
5. Install transfer pumping units on the main reservoir (R-11) to pump water to all the other reservoirs; this will require three transfer pumps, each with a capacity of 220 I/s and a 60-m head with the possibility of two additional pumps in the future,
6. Install two sets of irrigation pumping units at all new reservoirs; Each pumping unit set will consist of four pumps with a capacity of 60 m3/h each and 60-m heads, and (three duty pumps and one standby for each set),
7. Install satellite irrigation control and telemetry system.
Irrigation Pumping Units in Project B1:
Most of the reservoirs in Project B1 will have two pumping sets of irrigation pumps. Each set will consist of four pumps capable of delivering 60 m3/h with 60 m head. Normally three or four pumps will be operated for each set, depending upon the irrigation demand. However, if there is need for all four pumps to be operated, this will be possible.
Each pump will have variable speed control (Delta M-6 or similar) to maximize the efficiency of the unit and provide smooth operation. In some reservoirs, there will be only one set of pumps; however, there will remain the possibility of installing a second set at later stage or of increasing the pumps capacity. The total irrigation pump capacity for B1 is given in Table 7.
Transfer Pumps at the Main Reservoir (R-11) of Project B1:
Tree transfer pumps (two duty and one standby) will be installed at the main reservoir (R-11) to pumping water to the rest of the reservoir of Project B1. There are arrangements for installing two more in the future.
Each pump will have the following characteristics:
Q = 220 1/s, TDH = 60 m and Speed = 1450 RPM. However, the pumping unit’s capacity is inadequate, and steps should be taken to increase either the pumps capacity or to install additional pump’s. At present, the design includes two duty pumps with capacities of 200 1/s, for a total capacity of 440 1/s.
Transfer Lines in project B1:
There will approximately 67 km of main line varying in diameters from 250 to 1000 mm. For a distance of approximately 24 km detailed study, drawings preparation and releases obtained from the appropriate authorities will be needed. These transfer lines are located within Kuwait City, along Gulf Road, and in Salmiya, Rumaithiya and Salwa.
Satellite Irrigation Control and Telemetry in Project B1:
The satellite irrigation control and telemetry system will be similar to the one in Project A. In reality, it will be an expansion of the system, as it will be installed in the area Project A. All the information will be sent to the R-25 reservoir, which will be the main control office. Each reservoir in Project B1 will have an RTU which will communicate via radio signals with the main control office and with FCUs on which the remote control valves are connected via low- voltage wires.
Project B2:
Area Covered:
The area covered by this project is lies between the Ghazali Expressway on the west, King Faisal and Riyadh Street on the east, Gulf Road (from Ghazali to the Flag Area) on the north, and 6th Ring Road on the south (about 1 km south of 6th Ring Road).
Water Demand:
The peak daily irrigation water demand is estimated to be 5.1 mgd (23,180 m3/d).
Main Activities:
The main activities under Project B2 are as follows:
1. Delivery of water from the existing 1200-mm-diameter Riqqa line to the R-19 storage reservoir by gravity,
2. Construction of 25 new reservoirs, including R-19, which will be located next to the Riqqa main line,
3. Upgrade an existing reservoir at the Rabiya experimental station,
4. Construct transfer main lines from the main reservoir R-19 to all new reservoirs,
5. Provide connection of the Ardiya pumping station and the transfer lines with those of Project A and B1.
6. Install transfer pumping units at the main reservoir (R-19) to pump water to all the other reservoirs; there will be three transfer pumps, each with capacity of 220 1/s and 60 m head (two duty and one standby),
7. Install two sets of irrigation pumping units at each new reservoirs. Each set of pumping units will consist of four pumps with capacities of 60 m3/h each and 60 m (three duty pumps and one standby).
8. Install the satellite irrigation control and telemetry system.
Reservoirs in Project ‘B2’:
Detailed information on the reservoirs in Project B2 is provided in Table 6.
Irrigation Pumping Units in Project B2:
Four out of the five reservoirs in Project B1 will have two pumping sets of irrigation pumps. Each set will consist of four pumps capable of delivering 60 m3/h at 60 m head per pump. Normally three pumps for each set will be operated depending upon the irrigation demand. However, if there is need for all four pumps to be operated, this will be possible.
Each pump will have variable speed control (Delta M-6 or similar) to maximize the efficient of the unit and to provide smooth operation. In the R-34 reservoir and the reservoir in Rabiya there will be two sets of pumps; however, the pumps will have smaller capacities (total of 180 m3/h).
The total irrigation pump capacity for Project B2 is given in Table 9:
Transfer Pumps in Main Reservoir R-11 of Project B2:
Tree transfer pumps (two duty pumps and one standby) will be installed at the main reservoir (R-11) to pump water to the rest of the reservoirs of Project B2.
Each pump will have the following characteristics: Q = 220, TDH = 60 m and Speed = 1450 RPM. However, the pumping unit capacity is inadequate, and steps should be taken to increase either the pumps capacity or to install additional pumps. Presently the designs include two duty pumps with capacities of 220 l/s, for a capacity total of 440 l/s.
Satellite Irrigation Control and Telemetry:
The satellite irrigation control and telemetry system will be similar to the ones in Projects A and B1. In reality it will be an expansion of the system as it will be installed in areas A and B1. All the information will be sent to Reservoir R-25. Each reservoir in Project B2 will have a RTU which will communicate via radio signals with the main control office and with the FCUs on which the remote control valves are connected via low voltage wires.
Central Satellite Telemetry Irrigation Control System:
In all project areas (A, B1 and B2) of Phase I, a central satellite irrigation control system will be installed with a master control station at (R-25). The first portion of this system will be in operation by the middle of 1997, when the urgent Project A will be completed.
The satellite irrigation control system will be based on a radio link between the master control station, the RTUs near the reservoirs and pumping stations and the FTUs which will be located in the landscaped areas connected to a number of solenoid valves through wires. The communication will be done on one channel with a frequency in the range of 376 to 376.225 MHz.
The frequency of channels between RTUs and FCUs has to be repeated in different areas to minimize the number of channels required. Care should be taken to avoid interference or overlapping between two channels on the same frequency.
Master Control Station:
The Master Control Station will be housed in an office already under construction near the Reservoir R-25. The selection of this location was based on its easy access and its location almost in the middle of the Phase I area. The radio signals from this location can reach to a distance of at least 10 km with enough power and little interference for linking to the RTUs which will be located at the various reservoirs of the area. It must be remembered that will the full development of Phase I, there will be 41 reservoirs, each having an RTU.
The master control station will consist of a distributed process controller with a transceiver with 5 W of power, a file server, a Omni directional antenna 10 m in height, computer facilities and a display minic panel. The distributed process controller that has been approved is the BBL DPC 3330 series manufactured by British Babcock, UK, which will communicate with the RTUs and FCUs to receive and transmit all data format to the field.
The file server is the VAX 3100 model 85. Other components of the master control station include:
1. Engineer console consisting of a 14 in video monitor and a dot-matrix printer,
2. Operating station consisting of a 486 DXZ CPU with 8 MB of RAM, a 20 in video display unit and a keyboard,
3. Report and alarm laser printers.
4. Uninterrupted power supply (187-264 VAC single) providing an output of 230V AC at 50 Hz,
5. Mimic panel (6 m × 2 m) installed during Project B1, execution showing all the areas of Kuwait City served, the main components of the system reservoirs status, pump status, etc.
Remote Terminal Units (RTUs):
The RTUs are intelligent equipment, and will receive and transmit data to the master control station at Reservoir R-25. They transmit messages to the FCUs to start/stop irrigation at specific remote control valves. All RTUs will have a +3db Yagi directional antenna mounted on a three meter or six meter support.
A radio survey has been carried out within the Phase I project area to determine the power of transceiver and the height of the antenna needed for the master station, RTUs and FCUs. The results were satisfactory, and no serious problems were observed. However, in problematic areas where there are obstacles, then the power of the transceiver and the antenna height have to be increased.
The main function of the RTUs will be to:
1. Monitor the level of the reservoirs,
2. Monitor the overflow of the reservoirs,
3. Monitor the status of the transfer pumps,
4. Monitor the status of the irrigation pumps,
5. Monitor the flow of water in the pumping stations or in any other portion of the irrigation network,
6. Monitor the pressure at the pumping stations or in any other portion of the irrigation network,
7. Monitor the power supply/failure (ON/OFF),
8. Monitor the operation of the chlorine pumps (ON/OFF),
9. Monitor the operation of the water supply to the reservoirs by closing or opening the motorized butterfly valve in correspondence the level indicator of water in the reservoirs, and
10. Monitor the power supply to the irrigation pumps (ON/OFF)
11. Generate alarms as follow:
a. Low alarm for reservoir level,
b. High-high alarm for reservoir level,
c. Overflow alarm for reservoir level,
d. Chlorine gas leakages,
e. Power failure, and/or
f. High differential pressure in sand/screen filters.
Field Control Units (FCUs):
The FCUs will be installed at the location where the controllers for automatic irrigation within the landscaped area. The FCUs are connected to the remote control valves with low voltage cables (usually 14 gauge for the hot wires and 12 gauge for the common wires).
The FCUs will receive signals from the master station controller through the RTUs to initiate or end irrigation at a specific remote control valve. These units are ON/OFF only and are not intelligent, as are the RTUs. Each FCU will have a minimum of 16-digit output and four analog input, i.e., it can accommodate 16 remote control valves to and have up to four flow/pressure/moisture sensors.
Through the radio survey carried out, it was found that the transmitter should have a power of 0.3 W and an antenna height of three meters. The antenna will be also +3db Yagi directional. In problematic areas where there are obstacles, the antenna height may have to be increased to sixth meters for better reception of the signal transmitter from the RTUs. The RTUs will be serially polled by the distributed process controller at the master control station (R-25). The polling cycle will not exceed two minutes including interruption by an emergency control signal.
Each FCU will be polled serially by the RTU. Each RTU will have the capacity to poll serially up to 40 FCUs. The total time required to complete the polling cycle will be 120 sec (two minutes). The period of two minutes is considered satisfactory for an emergency alarm situation, i.e., the data will be updated every two minutes.
Remote Control Valves (RCV):
Remote Control Valves are usually of one to two inches in size, with bronze or plastic bodies and a pressure regulating element. Low- voltage cable connects the RCVs with the FCUs.
Weather Station:
A weather station recording all climatic measurements collected will transfer all the information to the master control station to alter the irrigation scheduling in accordance with prevailing conditions.
Sensor and Alarms:
Sensors will be installed in the pumping stations and reservoirs as well as on any part of the irrigation network where they may be required.
Software:
The software will be prepared to meet the requirements of the system and the irrigation commands, and will conform to the open-system standard software.