1. GENERAL: This is a non-personnel services contract to provide Industrial Water Treatment (IWT) of Closed Loop hot and chilled water systems on Kunsan Air Force Base as defined in this Performance Work Statement (PWS). The Government will not exercise any supervision or control over the contract service providers performing the services herein. Such contract service providers shall be accountable solely to the Contractor who, in turn in responsible to the Government. 1.1. Description of Services/Introduction: The contractor shall provide all labor, supervision, equipment, tools, expendable materials, transportation, and other items and services, necessary to perform Industrial Water Treatment (IWT) of closed loop hot and chilled water systems services, as defined in this Performance Work Statement (PWS) at Kunsan Air Base (AB). The facilities requiring these services are listed in Technical Exhibit (TE) #1, Workload Estimates (Facility Listing). 5. SPECIFIC TASKS: 5.1. Monthly Water Treatment and Analysis: The contractor shall analyze and treat the water of existing water distribution systems for hot water boilers and chilled water systems so that this water is maintained according to the Recommended Parameters of Each System in the TE #2. Note that these parameters in TE #2 are listed only so as to give the contractor guidelines, and the appropriate values are a function of the condition of make-up water. The contractor shall make all necessary efforts to maintain those parameters at the appropriate value through frequent make-up water analysis (i.e., seasonally) and treat the water accordingly. Any significant changes to these parameters shall be brought to the attention of the COR in writing, and the COR must provide written approval if no further treatment is to be made to adjust a parameter that has undergone a reported significant change. 5.1.1. The contractor shall be responsible for the type of chemicals and dosing quantities selection based on the water volume of the system. The chemicals (such as scale & corrosion inhibitors or oxygen scavengers) shall be industrially proven in their performance and commonly used for closed heating and cooling systems. 5.1.2. The water sample shall be taken from the proper system sampling point and the contractor is responsible for wearing all protective devices and clothing while taking samples. 5.1.3. After analysis of before- and after-service water samples, the contractor shall submit a water analysis report to the COR within 7 working days of the next performance month. The water analysis report shall include, but not be limit to, data on the treated facilities' building number, sampling date, parameter values before and after treatment, and chemical types and their quantities used for treatments. If the recommended parameter values could not be achieved within a reasonable amount servicing due to existing system problems, the contractor shall report the reason for this failed service and any system irregularities (i.e., piping leak, system being labeled "out of service," etc.) for the government's remedy. The Recommended Record Forms is attached in TE #3. The list of facilities requiring these services are attached in TE #1. 5.1.4. The contractor shall use proven and calibrated water analyzers whenever sampled water is analyzed. Calibration data and frequencies are to be submitted to the COR. The analyzer shall be tested and certified to have calibration traceability back to an internationally recognized testing organization and the contractor shall provide this analyzer's certification or test report. If multiple analyzers are to be used, test reports and/or certificates shall be provided for each respective analyzer. These certifications shall be at least within a year of the measurements performed for this task, unless there are documented manufacturer recommendations that a longer period between calibrations is acceptable. 5.1.5. Leak Reports: The contractor shall report any leak within the mechanical room and/or in or around the area of the central heating and cooling system immediately upon finding. The report shall include, but not limit to, the facility number, a photo taken of the leaked, the date the leak or damage was discovered, detail information of the area (i.e., 4" hot water supply line 80 cm from hot water pump discharge), and recommended action to be taken. 5.1.6. The contractor shall be responsible for the removal of all hazardous waste that might be generated during the performance of this contract. And contractor shall contact COR immediately upon hazardous waste finding at the job site. 5.2. Water Volume Check: Whenever a water distribution system is changed or a new water system is installed, the contractor shall check the new water volume before deciding the initial quantities of chemicals. This work will be authorized separately by an issued delivery order from the contracting office. TECHNICAL EXHIBIT #2 RECOMMENDED WATER PARAMETERS OF EACH SYSTEM Note: As stated in the PWS 5.1, these parameters and recommendations are to be used as guidelines. These recommendations are the excerpt from the Industrial Water Treatment Primer formerly known as Air Force Instruction (AFI) 91-40, published by the Air Force Civil Engineering Support Agency (AFCESA). Based on make-up analysis and the condition of each system, each parameters and programs might be changed to apply the program more effectively. The contractor shall be responsible to update and validate those parameters regularly to give the Government's system the best corrosion/scale/other factor's rate to extend life cycle for all hot and chilled water systems in the Kunsan Air Base. HOT WATER HEATING SYSTEMS A. GENERAL A water treatment program for a hot water heating system is less complicated and less demanding than the treatment program for a steam heating system. Unlike a steam system, a hot water system is a closed system and does not require blow-down; therefore, system makeup should not exceed 5% of the system's volume/year. The chemicals used in a hot water system are retained within the system, making it cost-effective and easier to maintain. The following tasks should be accomplished before a water treatment program is initiated for a hot water heating system. 1. Make sure the system is free of leaks. 2. Install a backflow prevention device in the makeup water line. 3. Install a metering device. 4. Install a sample cooling coil. 5. Install a chemical feed system. 6. Install dielectric unions. B. TYPES OF HOT WATER SYSTEMS Low/medium temperature water systems do not require pretreatment of the makeup water unless the total hardness exceeds 50 ppm as CaCO3. Three treatment programs developed for closed systems are: 1. Sulfite-caustic soda program. 2. Nitrite-borax program. 3. Molybdate-caustic program. Nitrite-borax and molybdate-caustic treatment programs are usually the programs of choice for low/medium temperature systems because they are very effective at temperatures below 250oF. The treatment program is selected based on the metals in the heating system and the cost of the treatment program. Factors influencing the cost of a program include the size of the system, the amount of makeup water required, and the environmental or health restrictions. High temperature water (HTW) systems operate at 350oF to 420oF. The major concern for this system is to prevent scale deposition in the boiler tubes. Water softeners should be installed to remove 100% of the hardness contributing minerals from the makeup water. Scale on boiler tubes in a HTW system can lead to tube rupture or a boiler explosion. The chemical treatment program most often used for a HTW system is the sulfite-caustic soda program. C. TREATMENT PROGRAMS 1. Nitrite-Borax Treatment Program a. For the initial dosage, add approximately 18 lbs of sodium nitrite-borax for every 1000 gallons of water in the system. Enough sodium nitrite-borax should be added to sustain a nitrite residual of 1000 ppm as nitrite (NO2). b. Maintain a nitrite residual of 600 to 1000 ppm. c. Add sodium carbonate to maintain the pH at 8.5 to 9.5. d. Check pH and analyze the system water to determine the nitrite content 24 hours after initiating treatment. e. Make necessary adjustments, if needed. 2. Molybdate-Caustic Soda Treatment Program a. For the initial dosage, add approximately 12 lbs of sodium molybdate for every 1000 gallons of water in the system. Enough sodium molybdate should be added to sustain a molybdate residual of 125 ppm as MoO4. b. Maintain a Molybdate residual of 100 to 125 ppm. c. Add sodium hydroxide to maintain the pH at 8.5 to 9.5. d. Check pH and analyze the system water to determine the molybdate content 24 hours after initiating treatment. e. Make necessary adjustments, if needed. 3. Sulfite-Caustic Soda Treatment Program a. For the initial dosage, add approximately 1 lb of sodium sulfite and 2 lbs of sodium hydroxide for every 1000 gallons of water in the system. b. Maintain a sodium sulfite residual of 50 to 100 ppm as SO3. c. Add sodium hydroxide to maintain the pH at 9.0 to 10.0. d. Check pH and analyze the system water to determine the sulfite content 24 hours after initiating treatment. e. Make necessary adjustments, if needed CHILLED WATER SYSTEM A. GENERAL Protection of closed recirculating water systems generally features a high pH which is most often held between 8.5 and 9.5. Corrosion of mild steel is reduced substantially at high pH. However, systems with unresolved leaks can expect scale deposits if the hardness mineral content in the makeup water is high. Within this narrow pH range, the choice of corrosion inhibitor is more limited than for open systems. The most common corrosion inhibitor for chilled water systems is referred to as boron nitrite. It uses borax as a buffering agent to maintain a pH above 8.5 and usually contains a variety of corrosion inhibitors that includes sodium nitrite, sodium silicate, and copper corrosion inhibitor. Though rather effective, this treatment is not without shortcomings. Both the boron and nitrite are toxic to humans and cannot be used in food-processing plants. Nitrite is an excellent nutrient for bacteria growth. If bacteria enter this system, it can destroy the nitrite, produce low pH levels, and produce slime deposits as well. Finally, if air enters the system at points such as pump seals, nitrite converts to nitrate, which is not as effective for corrosion control. Molybdate-based treatments have found recent use with considerable success. They often contain copper corrosion inhibitors and occasionally an alkali buffering agent to maintain pH above 8.0. The molybdate is maintained at levels of 100-200 ppm (as MoO4). This treatment is not toxic, is environmentally acceptable, and does not contribute to biological growth. B. TREATMENT PROGRAM FOR CHILLED WATER SYSTEMS 1. Nitrite-Borax. a. Soften makeup water if hardness is over 250 ppm as CaCO3. b. Maintain 600-1000 ppm as NO2. c. Add sodium carbonate to maintain a pH range of 8.5 to 9.5. d. Prevent degradation of nitrite, supplement with a biocide. 2. Molybdate-Caustic Soda. a. Soften makeup water if hardness is over 250 ppm as CaCO3. b. Maintain 100 to 125 ppm molybdate as MoO4. c. Add sodium hydroxide to maintain a pH range of 8.0 to 9.0.