Appendix_7_-_Chemical_Treatment.pdf

Appendix 7

NNG16572637R

CHEMICAL TREATMENT

CHEMICAL TREATMENT

1.0 Introduction.

Goddard Space Flight Center currently treats its water and steam systems inside the Central

Power Plants and in the buildings with a variety of chemicals. The Contractor shall be responsible for the continued treatment of the water and steam systems.

The objectives of the water treatment program are to minimize, to the extent practical, the effects of water and biological agents on the metal surfaces inside the building’s cooling tower, chilled water, steam generating systems, and other closed water systems in order to prolong the life and maximize the effectiveness of these systems.

The purpose of this specification is to provide an accurate and detailed description of the requirements of a water treatment program such that diligent adherence to these requirements will result in attaining the objectives of the water treatment program. Appendices 15a through

15d are information provided on facility information, historical chemistry data, and permits.

2.0 Requirements

The water treatment program for each system shall be installed and implemented by the

Contractor to ensure that each system operates without failure or reduced performance caused by deposition, corrosion or microbiological contamination of the water-contacted surfaces. The success of the program will be judged both by how closely the treatment program adheres to the pre-established performance criteria described in this specification, and by the condition of critical surfaces of system components as revealed during periodic inspections. Inspections shall indicate that there is no significant corrosive attack on any metal in contact with treated water or accumulation of excessive scale, deposition, and/or biological growth on system surfaces.

The water treatment program is a joint effort between the Contractor and the Government. The

Plant Supervisor may be either a government employee or a contract employee. The Plant

Supervisor will conduct frequent testing of critical parameters to monitor the program’s performance. The Contractor shall conduct additional, more in-depth testing during each service call to verify that water treatment parameters meet performance criteria.

The Contractor shall furnish all necessary treatment chemicals, chemicals delivery to the point of application, storage containers, secondary containment, safety equipment for chemicals and pumps, and documentation required in the storage of chemicals, such as MSDS sheets. All bulk deliveries shall be by drum less delivery system and all shipping containers shall be removed by the Contractor.

The Contractor shall furnish all test equipment, apparatus, reagents, and supplies. Testing equipment shall include a digital colorimeter for all applicable tests; a Hach DR 890 or equivalent is the minimum acceptable testing equipment. Suitable testing equipment already owned by the Government does not need to be replaced, but reagents and supplies shall be compatible with current test apparatus, or replaced. All test methods shall be verifiable by independent tests for precision and accuracy.

The Government will bring in its water treatment consultant, on a quarterly basis to do independent water sampling and to discuss performance with the Government and the

Contractor. The consultant will also inspect chillers and boilers when they are opened for cleaning. The Government will use the consultant’s recommendations for actions necessary for the chemical program to meet the specification requirements as guidelines to assure quality of the program.

The water treatment program shall include only those products listed in the Program Calculation

Sheets, contract Attachment F-1, or those products approved for usage in the contingency plans

(see Section 8.0). The composition of active ingredients shall not be changed without approval by the COTR who will obtain approval from Maryland Department of the Environment (MDE).

The water treatment program (described herein) shall be brought into full operation by the

Contractor within 30 calendar days of the date of contract award. All equipment changes shall have been completed by this date, and all indicator and control test parameter measurements and concentrations brought within the specified ranges.

2.1 Government Furnished Equipment

Government-furnished equipment includes the chemical feed pumps, the chemical injection lines and quills, testing equipment (Hach DR/890 colorimeter and sensION 156 pH/Conductivity meter with docking stations), coupon racks, and conductivity controllers with blowdown control.

The Government will be responsible for replacement and major repairs, and will purchase other equipment deemed necessary for the implementation of this contract.

The Contractor shall maintain this equipment in good condition according to manufacturers’ recommendations.

The operation and maintenance of the makeup water softeners and feedwater polishers are included in the central plant operations/maintenance.

2.2 Health, Safety and Environmental Requirements

The Contractor shall comply with all local, Maryland and federal regulations governing safety, health, and environmental protection. All chemicals shall comply with health and safety requirements, and be supplied with full Health and Safety documentation including Material

Safety Data Sheets (MSDS).

All chemicals used to treat the boiler system and cooling towers shall comply with GSFC’s

National Pollutant Discharge Elimination System (NPDES) permit for discharge to the waters of

Maryland. The Contractor shall provide MSDS and aquatic toxicity data to the Government prior to initial use of any chemical in these systems, for review and approval by the

Environmental Office. If the product name changes, but not the chemicals, the Contractor shall provide MSDS information to the Government at the time of the change, for use of the

Environmental Office.

All chemicals used to treat the boiler system and the chilled water systems shall comply with

GSFC’s Industrial Waste Permit from the Washington Suburban Sanitary Commission (WSSC).

The Contractor shall provide MSDS information to the Government six weeks prior to initial use of any chemical in these systems. If the product name changes, but not the chemicals, the

Contractor shall provide MSDS information to the Government at the time of the change.

2.3 Submittal Requirements

The Contractor shall provide all materials and perform all work required for furnishing submittals to the Government, in accordance with provisions, clauses, and paragraphs of this

Water Treatment Program Specification.

For each system, the Contractor shall submit the following information, separately each for the

Base Program and for its proposed Alternate Program:

(i) Program Calculation Sheets. Program Calculation Sheets for each system in each building.

One Program Calculation Sheet shall be completed, as a total program, for each system being treated. All treatment chemicals to be added to the system shall appear on the sheet. An additional Program Calculation Sheet (marked as the alternative program) shall be submitted showing all treatment chemicals offered in the alternative program, even if only one product changes from the Base Program. Each sheet shall describe a total program. The Program

Calculation Sheet is a Microsoft Excel spreadsheet in Attachment F-1 of this document. Once approved by the COTR, the completed Program Calculation Sheets will be incorporated as

Attachment F-1, "Program Calculation Sheets" of the Water Treatment Program Specifications.

(ii) Program Monitoring Sheets. Program Monitoring Sheets shall be completed for each program. One set of Program Monitoring Sheets needs to be completed for each type of program

(Base and Alternate). There are blank program monitoring sheets for evaporative cooling systems, closed systems, and steam boiler system. The Program Monitoring Sheet is a Microsoft

Excel spreadsheet in Attachment F-2 of this document. Once approved by the COTR, the completed Program Monitoring Sheets submitted with the successful offer will be incorporated as Attachment F-2, "Program Monitoring Sheets" of the Water Treatment Program

Specifications.

The Contractor shall assess the suitability of existing chemical dosing and control equipment to implement its Base and Alternate programs to meet the Specifications requirements. Separately for both the Base and Alternate programs, the Contractor shall submit the list the Chemical

Dosing and Control Equipment (new and/or existing) that it will need to implement each program. For new chemical dosing and control equipment and accessories, include the individual cost of each piece of equipment, the model number and specifications.

The Government will complete review of submittals, or resubmittals, for approval, within 14 calendar days of receiving a complete set of all the submittal materials required for a particular submittal. If the Government uses time in excess of the specified number of calendar days for review of any submittal or resubmittal, additional time, not to exceed the excess time, will be added to the time allowed the Contractor for performance of the service.

After the Government’s review, one set of submittals requiring approval will be returned to the

Contractor either approved, not approved, or conditionally approved; any required changes will be marked. Submittals that are not approved or that require changes or revisions shall be revised and resubmitted for approval, and shall show changes and revisions with revision date. All requirements specified for the initial submittal shall apply to any resubmittals required. All submittals which are to be resubmitted shall be resubmitted by the Contractor within 5 calendar days after the Contractor has received the Government’s comments, except as otherwise defined in this Specification.

2.4 Base Program and Alternate Program Requirements

The Contractor's Base Program, for each system type, shall include the following elements as a minimum:

Open Condenser Water Systems:

All programs (Base or Alternate) shall include a minimally reactive component in each non-biocidal product to use as a reference or tracing species used to track and control the product application. Molybdenum is the expected tracing element.

The Contractor shall provide, as a minimum for non-oxidizing biocide the following: 120 parts per million (ppm) of 45% glutaraldehyde per application, once per week.

The Contractor shall provide a minimum of twice daily (or continuous) halogenation utilizing stabilized liquid bromine, maintaining a free and available halogen residual of 0.3 – 0.5 ppm, and a free halogen residual of 1 ppm for 4 hours, once per week.

For the purposes of specification calculations, use 10 cycles of concentration for evaporative cooling towers.

Closed Systems:

The closed system corrosion inhibition shall be nitrite based, unless there is a documented biological contamination of the system evidenced by significant nitrite to nitrate reversion or documentation of denitrifying bacteria.

The Contractor shall provide, as a minimum for non-oxidizing biocide the following: 240 of ppm

1.5% isothiazolone, per application, once per year. An alternate biocide may be proposed.

Steam Boiler System:

The Contractor shall provide, as a minimum, a sulfite based oxygen scavenger for the steam boiler system. The oxygen scavenger is currently fed to the storage section of the deaerator.

The Contractor shall provide, as a minimum, a polymer based boiler water program for the steam boiler system. The polymer is currently fed at a common point in the feedwater line, after the feedwater pumps, in proportion to the flow, and feedwater demand. Currently, the adjustments to the feedrate of Polymer is addressed manually, on a daily basis.

Boiler blowdown is controlled by individual automatic continuous conductivity controllers.

The Contractor shall provide, as a minimum, a liquid, blended steam condensate neutralizing amine corrosion inhibitor suitable for the campus distribution system and acceptable for humidification and direct steam injection. The amines are currently fed at a common point in the feedwater pumps.

1.0 CORROSION/DEPOSIT INHIBITOR PROGRAM: Open Condenser Water and

Closed Systems

3.1 General

The corrosion/deposit inhibition program shall ensure satisfactory control of corrosion and deposition and comply with the performance criteria given in Section 3.5.

Satisfactory corrosion control shall be achieved for system metals, which may include the following: mild steel, stainless steel, and copper. Metals present in each of the buildings’ systems are given in the Building Information Summary.

3.2 Chemical Treatments: Open Condenser Water Systems

In order to minimize water consumption on site it is intended to operate the cooling systems at maximum “Cycles of Concentration.” “Cycles of Concentration” is the water treatment industry term for the concentration factor of dissolved constituents. For example, copper in a system’s water at concentrations three times that of the make-up water is said to have three “cycles of concentration.” This concentrating effect is largely a result of evaporation. Generally, all dissolved constituents shall have the same concentration factor, and when this reaches a predetermined limit, make-up water is introduced to prevent the dissolved constituents from becoming even more concentrated, as too high a concentration has deleterious effects. The target value is determined by the local limiting species, and shall be achieved gradually over a period of time. The corrosion and deposition program shall operate in the alkaline pH range which shall be accounted for in the selection of treatment chemicals.

3.2.1 Corrosion/ Deposit Inhibitor

The corrosion inhibitor shall be molybdenum/zinc/phosphonate/azole based. Molybdenum is required as a tracing component. Nalco “TRASAR” is also acceptable. All open systems contain copper or its alloys and as such shall be treated with a suitable, copper-specific inhibitor, and maintain a minimum positive residual of inhibitor at all times. The corrosion inhibitor is critical in the open systems, due to the extreme corrosivity of the makeup water source.

Deposit inhibitor and corrosion control may be combined in a single liquid treatment.

The proposed product name(s) shall be specified in the Program Calculation Sheet, Evaporative

Tower Water Systems appearing in contract Attachment F-1. The approved product(s) may not be changed without prior approval of the Government.

The proposed approved application concentration range of the product(s) and testing control parameter(s) concentration range(s) shall be also entered in the Program Calculation Sheet, Evaporative Tower Water Systems appearing in contract Attachment F-1. These may also not be changed without the prior approval of the Government.

Monitoring requirements of the control parameter(s) and other parameters important to the maintenance of sufficient levels of corrosion/deposit inhibitor chemicals shall be specified in

Section 3.4.2.

3.2.2 Dispersant / Deposit Inhibitor

The proposed dispersant product name, or the dispersant compound(s) if combined in the corrosion inhibitor formulation, shall be specified on the Program Calculation Sheet, Evaporative

Tower Water Systems appearing in contract Attachment F-1. The approved product or compound may not be changed without prior approval of the Government.

The proposed dispersant application and control parameter concentration ranges are entered on the Program Calculation Sheet, Evaporative Tower Cooling Water Systems that appear in contract Attachment F-1. These may not be changed without the prior approval of the

Government.

Monitoring requirements of the indicator and control parameters important to the maintenance of sufficient levels of corrosion/deposit inhibitor chemicals are specified in Section 3.4.2.

3.3 Chemical Treatments: Closed Systems

3.3.1 Corrosion/Deposit Inhibitor

The corrosion/deposit inhibitor product shall be free of all glycols. The product shall provide a minimum applied concentration of 100 mg/l molybdenum (Mo+6) or 500 mg/l of nitrite (NO2) as the primary steel corrosion inhibitor.

All systems contain copper or its alloys, and shall also be treated with a suitable, copper-specific inhibitor, and maintain a minimum 5 ppm residual of inhibitor.

Until the loss of water from the West Campus chilled water system is brought under control, that system shall be treated with an alternate program. A silica-based program is acceptable.

The approved corrosion/deposit inhibitor products shall be specified in the Program Calculation

Sheet, Chilled or Hot Water Closed System sheets and appear in contract Attachment F-1. The products may not be changed without prior approval of the Government.

The approved application concentration ranges of the products and testing control parameter(s) concentration range(s) shall be also specified in the Program Calculation Sheet, Chilled or

Closed Water System sheets, and appear in contract Attachment F-1. These may also not be changed without the prior approval of the Government.

Monitoring requirements of the control parameter(s) and other parameters important to the maintenance of sufficient levels of corrosion/deposit inhibitor chemicals are specified in Section

3.4.2.

3.3.2. Dispersant

The chilled and hot water closed system treatment programs shall include a polymeric dispersant able to disperse corrosion products and foulants in the systems.

The Program Calculation Sheet, Chilled and Hot Water Closed Systems, contract Attachment F-

1 shall list the approved treatment products, components and applied concentrations. Provide treatment level for all components, recommended feed points, container size, material and type.

Product shall be free of all glycols and be compatible with glycol in glycol treated systems.

The approved dispersant product name and application concentration range shall be specified in the Program Calculation Sheet, Chilled and Hot Water Closed System sheet(s) that appears in contract Attachment F-1. The approved product(s) and their application range(s) may not be changed without prior approval of the Government.

The approved application concentration range of the product(s) concentration range(s) are also entered in the Program Calculation Sheet, Chilled or Hot Water Closed System sheet(s) that appear in contract Attachment F-1. These may also not be changed without the prior approval of the Government.

3.4 Monitoring Requirements

3.4.1 Coupon Rack

Coupon racks shall be used by the Contractor for the purpose of monitoring the effectiveness of the corrosion control for each of the metals in the system. Each evaporative tower and closed or chilled water system shall have coupon racks for the purpose of monitoring corrosion.

Corrosion rates shall be monitored in situ by utilizing pre-weighed coupons in accordance with accepted methods (such as American Society for Testing and Materials (ASTM) G4-95). See

Section 6.1.5 for further details on coupon rack construction requirements.

Coupons shall be weighed every 6 months and semi-annual corrosion rates calculated to mils per year with an accuracy of 0.1 mils. The performance criteria for the various metal coupons are specified in Section 3.5.1.

Quarterly coupon data shall be presented in the Service Reports described in Section 7.2.2.

3.4.2 Water Chemistry Monitoring

At a minimum, weekly water chemistry testing shall be conducted by the Contractor. At the discretion of the Government, the testing frequency may drop to bi-weekly when the systems are deemed by the Government to be in control.

The basic testing requirements are listed in Table 3.1 below.

Table 3.1 Tests by Contractor, Open Condenser Water and Closed Water Systems

Treated

System Indicator/Control Parameters Frequency

Make Up Water pH

Conductivity

Calcium

Silica

Weekly

Open Water

Systems pH

Conductivity

Steel Corrosion Inhibitor control parameter

Copper Corrosion Inhibitor control parameter

Iron

Calcium

Silica

Weekly

Closed Water

Systems pH

Conductivity

Steel Corrosion Inhibitor control parameter

Copper Corrosion Inhibitor control parameter

Iron

Monthly

Open and

Closed Water

Systems

In lieu of field tests for copper, the contractor shall conduct a inductively coupled plasma (ICP) laboratory analysis of total copper, dissolved copper, and copper inhibitor concentrations.

Semi-annually

The Plant Supervisor will monitor the following:

Table 3.2 Tests by Plant Supervisor, Open Condenser Water and Closed Water Systems

System Indicator/Control Parameters Frequency

Make Up Water pH

Conductivity

Daily

Open Water

Systems pH

Conductivity

Steel Corrosion Inhibitor control parameter

Daily

Closed Water

Systems pH

Conductivity

Steel Corrosion Inhibitor control parameter

Test kits and replenishment supplies shall be provided by the Contractor to enable required monitoring of the indicator and control parameters at the frequency specified in Table 3.2 above.

Furthermore, the Plant Supervisor shall be provided detailed instructions on sampling and testing for all of the parameters. See Section 6.1.6 for the minimum specifications on the chemical testing equipment to be supplied.

The instructions for testing for each of the analyses and other documentation, shall be provided by the Contractor to the Plant Supervisor and included in the Water Treatment Manual. See

Section 6.2 for a list of the documentation to be provided and description of how the manual is to be used.

3.5 Performance Criteria

The Plant Supervisor and the Water Treatment Consultant will inspect the Chiller condenser tubes during annual cleaning of the condensers. Condenser or closed system components may also be opened and available for inspection during other repair or replacement operations. At such times, the Contractor shall be present, and inspect critical components to evaluate a system’s condition. In the event that excessive deposition or corrosion is discovered by these inspections, the Contractor shall prepare an Out of Compliance Notice Report (Section 7.2.1) and include a recommendation for remedying the condition.

The Condenser Water system shall be free of abnormal deposition or evidence of internal corrosion that should be controlled by proper water treatment chemistry and control.

3.5.1 Corrosion Inhibition: Coupons

The minimum satisfactory corrosion performance criteria for each of the system coupons are as follows:

Table 3.3 Coupon Performance Criteria, Cooling Systems

Metal Performance Criteria

Open Systems Mild Steel (Low carbon steel)

Not to exceed one (1) mpy (mils per year)

Stainless Steel Not to exceed one half (0.5) mpy

Copper Not to exceed one tenth (0.1) mpy

General No excessive pitting corrosion

Closed Systems Mild Steel (Low carbon steel)

Not to exceed one half (0.5) mpy (mils per year)

Stainless Steel Not to exceed one half (0.5) mpy

Copper Not to exceed one tenth (0.1) mpy

General No excessive pitting corrosion

If these performance criteria are not achieved, then the corrective actions specified in Section

3.6.1 shall be taken.

3.5.2 Corrosion Inhibition: Chemical Treatments

Chemical treatments, as monitored by testing for the control parameters described in Section

3.4.2, shall be maintained within the concentration ranges that appear in the Program Monitoring

Sheets in contract Attachment F-2.

Conditions may occur that prevent the achievement of the required concentration. Some of these circumstances are described in Section 8. If the performance criteria (control and indicator parameters identified in contract Attachment F-2) cannot be met within one month following the first instance of the failure to meet the performance criteria, whether obtained by the Contractor or the Plant Supervisor, then the corrective action described in Section 3.6.2 shall be undertaken.

Similarly the corrosion indicators, iron and copper, are considered excessive within the circulating water, and possibly indicative of corrosion within the system, if their cycles of concentration exceed the system cycles of concentration by more than three. If the Contractor finds an excess of three or more cycles of concentration for copper or iron for more than one month, then the corrective action specified in Section 3.6.2 shall be undertaken.

All closed and chilled water systems shall maintain a minimum positive residual of copper-specific inhibitor, for example azole, of 5.0 mg/l. The determination of residual azole is: total azole mg/l – (2 x total copper mg/l) = residual azole. The Contractor shall use test results provided by the Government, or conduct tests for total copper as per Table 3.1 to allow accurate calculation of residual inhibitor.

All open systems shall maintain a minimum positive residual of copper-specific inhibitor, for example azole, of 1.0 mg/l at all times. The determination of residual azole is: total azole mg/l

– (2 x total copper mg/l) = residual azole mg/l. The Contractor shall use test results provided by the Government or conduct tests for total copper as per Table 3.1 to allow accurate calculation of residual inhibitor.

3.5.3 Deposit Control

Satisfactory deposit control shall be achieved. Deposition in condenser tubes shall be controlled to maintain the specified design fouling factor or overall heat transfer co-efficient or both.

To monitor deposition on a regular basis, mass balance computations of several control and indicator parameters shall be computed and included in the Service Report (Section 7.2.2). To perform the mass balance, the cycles of concentration shall be compared for calcium, magnesium and silica, conductivity, iron and copper parameters.

To calculate cycles of concentration the following formula shall be used:

Cycles of concentration = Parameter in recirculating water

Parameter make-up water

Example: Cycles of Concentration = Calcium (mg/l) in tower water

Calcium (mg/l) in the make-up water

System deposition control is indicated when there is agreement on the cycles of concentration for each parameter. If the cycles of concentration do not agree within +/- 1.0 cycles of concentration, then a precipitation mechanism shall be assumed and the corrective action described in Section 3.6.3 shall be taken.

3.6 Corrective Actions

Corrective actions shall be taken immediately after the identification of an out of compliance condition. Day-to-day adjustments in treatment applications may be made by the Plant

Supervisor who will follow the Corrective Action Flowchart (Section 6.2.2) provided by the

Contractor, or by the Contractor during the scheduled service calls (Section 7.3), but when performance criteria are not being met, more serious action may be required. Furthermore, if the condition is not remedied by the next sampling period, and out of compliance notification

(described in Section 7.2.1) may be required, which entails a more thorough review of the system or of the program’s design. Actions are described for each of the program’s performance criteria with respect to the corrosion/deposit inhibitor program in the sections below.

3.6.1 Excess Coupon Corrosion

Corrosion rates, as indicated by an exceedence of allowable coupon corrosion or excursions of the approved range of control parameter concentrations, shall be brought into compliance with section 3.5.1 within six months of contract award and within three months of start-up following a system shutdown.

If the specified performance criteria listed in section 3.5.1 are not achieved within six months from contract initiation or three months of start-up following a system shutdown, or if the specified criteria are not met at any regular quarterly sampling event, corrective action shall be taken within one week of the receipt of the laboratory results by the Contractor. If the next scheduled quarterly sampling period indicates that the criteria have still not been met, the

Contractor shall submit an Out of Compliance Notice Report as described in Section 7.2.1 with a recommended course of action to achieve the performance criteria.

3.6.2 Out of Range Corrosion Indicator/Control Parameters

If either the steel or copper corrosion inhibitor control parameters (listed in contract Attachment

F-2) cannot be brought to within the required range within one month of being determined to be out of range, then the Contractor shall submit an Out of Compliance Notice Report as described in Section 7.2.1. The Out of Compliance Notice Report shall include the probable cause and remedy.

Corrosion indicators, iron and copper, are considered excessive, and possibly indicative of corrosion within the system, if their cycles of concentration exceed the system cycles of concentration by more than three (see computational method in Section 3.5.3), the Contractor shall file an Out of Compliance Notice Report as described in Section 7.2.1. The Out of

Compliance Notice Report shall identify the cause for the cycle’s variance, along with a plan to address the conditions.

3.6.3 Out of Range Deposition Indicator Parameter

If the cycles of concentration of calcium, magnesium or silica do not agree within +/- 1.0 cycles of concentration, then a precipitation mechanism shall be presumed and remedial action shall be taken. The Contractor shall present the cause for the cycles variance and a comprehensive plan to address the conditions in an Out of Compliance Notice Report (Section 7.2.1).

4 MICROBIOLOGICAL CONTAMINATION CONTROL PROGRAM

4.1 Microbiological Control: Open Condenser Water Systems

4.1.1 Oxidizing Biocides

The required method of oxidizing biocidal treatment for cooling towers is the twice daily (at a minimum – continuous application is preferred) application of an oxidizing biocide to attain a free and available halogen residual in the recirculating water. Once per week, the free halogen feedrate shall be increased to provide a higher residual of halogen for 4 hours. These residuals are defined in Section 4.4.6.

Monitoring for the presence of residual free halogen shall be conducted in the manner and frequency described in Section 4.3.3.

A biodispersant may be used to minimize biofilms.

4.1.2 Non-Oxidizing Biocides

The oxidizing biocide shall be backed-up with a weekly slug dose of non-oxidizing biocide with proven efficacy against Legionella. The purpose of non-oxidizing biocides is to provide better penetration into biofilms and deposits and, in conjunction with the oxidizing biocide, more effective control of a broad spectrum of anaerobic bacteria, especially sulfate reducing bacteria.

Non-oxidizing biocides shall be added proportionally to the system volume with an allowance for blow-down loss to maintain the required concentration in the system water for a minimum of four hours following commencement of treatment (period of dosing).

Non-oxidizing biocide application quantities shall be based on each individual system’s volume.

The Contractor shall verify the system volume.

The non-oxidizing biocide shall be applied weekly to each open cooling system. Testing shall be conducted as defined in Section 4.3.2 to verify control. Timing of the non-oxidizing feed shall be coordinated with the plant to ensure circulation through each off-line chiller.

Applications of biocide shall not exceed the limit on the MDE permit for the application to the type of system being treated.

4.2 Microbiological Control: Chilled and Hot Water Closed Systems

Microbiological control chemicals approved for chilled and hot water closed systems treatment appear on the Program Calculation Sheet, Chilled or Hot Water Closed Systems, in contract

Attachment F-1.

The microbiological control program for chilled and closed systems shall be monitored by the

Contractor as specified in Section 4.3.2.

The biocide application schedule shall be sufficient to meet the specified performance criteria given in Sections 4.4.1 through 4.4.5. A minimum of one application per year of microbiocide is required.

The Contractor shall verify the system volume.

4.3 Monitoring Microbiological Activity

4.3.1 Legionella Sampling, Open Condenser Water Systems

The Contractor shall test and report for Legionella semi-annually through a laboratory certified in the analysis and identification of Legionella. The prescribed corrective action for the control of Legionella shall be taken if the performance criterion is not met. The performance criterion is described in Section 4.4.2; the corrective action is described in Section 4.5.1.

The Government will be responsible for record-keeping requirements for the Legionella sample analysis results.

4.3.2 All Other Bacteria

Microbiological activity in these systems is the primary cause of system failures and shall be monitored carefully. The minimum testing requirements to be conducted by the Contractor for other bacteria are listed in Table 4.1, and by the Plant Supervisor in Table 4.2 below. Note that the indicated sampling frequencies are minimums only. In the event of an out of compliance condition the Contractor shall perform tests to ensure that corrective action is bringing the condition under control. The analytical methodologies to be employed are described after the tables. Additional microbiological testing shall be conducted as specified on the Program

Monitoring Sheets (all systems) that appear in contract Attachment F-2.

Table 4.1 Tests by Contractor, Microbiological Control

Treatment System Control Parameter and

Bacteria to be tested

Frequency

Make Up Water (Two wells)

Microbiological profile Semi-annually

Open Water Systems Free halogen

Total Heterotrophic Bacteria

Sulfate Reducing Bacteria

Iron-Related Bacteria

Weekly

Weekly

Semi-annually

Semi-annually

Closed Water Systems Total Heterotrophic Bacteria

Sulfate Reducing Bacteria

Iron-Related Bacteria

Monthly

Semi-annually

Semi-annually

The minimum testing and the frequency of testing to be conducted by the Plant Supervisor are given in Table 4.2 below. During any week in which there is a scheduled visit by the Contractor, the total heterotrophic bacteria test will be taken by the Plant Supervisor 48 hours beforehand so that the Contractor can undertake appropriate corrective action during the service visit.

Table 4.2 Tests by Plant Supervisor, Microbiological Control

Control Parameter and

Bacteria to be tested

Frequency

Make Up Water None -

Open Water Systems Free halogen

Total Heterotrophic Bacteria

3 x /week

Closed Water Systems Total Heterotrophic Bacteria

For routine monitoring of total heterotrophic bacteria, the dip slide method shall be employed with an incubation period of 48 hours at 35 oC., as stated in the monitoring requirements of the

United States Environmental Protection Agency's Surface Monitoring Water Treatment Rule (40

Code of Federal Regulations 141.74). Total colony counts of heterotrophic bacteria shall be determined using either the standard plate count method (American Public Health Association

Standard Method 9215), or Bacteriological Examination of Drinking Water Supplies (40 Code of

Federal Regulations 141.74). If repeated high readings are found using the dip slide method (104 or greater), verification via an approved plate count method shall be completed (see Section4.4.3 for performance criteria) and a biocide selection study shall be conducted by the Contractor.

Dip slide results, or total number of colony forming units if a confirmatory plate count method is used, shall be recorded as described in Section 7.2.2.

Sulfate reducing bacteria are recognized as aggressive anaerobic bacteria found on system surfaces and infrequently in the aerated bulk water. Their presence in the bulk water phase is an indicator that a more serious condition in the system exists and shall be addressed as described in

Section 4.4.4.

The Contractor shall perform a Biological Activity Reaction Test (BART) for sulfate reducing bacteria at the frequency specified in Table 4.1 above, to determine system biological condition and to characterize the existing bacteria. The results shall be provided to the Plant Supervisor within one week of completion of the tests. See Section 4.4.4 for information on the performance criterion on the analysis results of sulfate reducing bacteria.

The Contractor shall perform a BART test for iron- related bacteria, at the frequency specified in

Table 4.1 above, to determine system biological condition and to characterize the existing bacteria. Many iron-related bacteria are facultative anaerobes and will test under aerobic and anaerobic conditions. See Section 4.4.5 for the performance criterion of the analysis results for iron-related bacteria.

If the concentration of nitrite used as an iron corrosion inhibitor in a closed system cannot be stabilized within two months, the Contractor shall perform a BART test for nitrite reducing bacteria. See Section4.4.7 for the performance criterion of positive results for nitrite reducing bacteria.

4.3.3 Free Halogen Monitoring

The Contractor shall measure free halogen at the frequency indicated in Table 4.1 above. The tests shall be conducted employing the DPD colorimetric method using digital colorimetry. If the current control settings do not maintain free halogen within the specified limits, the

Contractor shall adjust the system settings or service the system.

Plant Supervisor will conduct free halogen tests at the frequency prescribed in Table 4.2 above.

The test method shall be a DPD colorimetric method using a digital colorimeter.

The performance criteria for free halogen in open water systems are described in Section 4.4.6.

1.1 Performance Criteria

The Plant Supervisor and the Water Treatment Consultant will inspect the Chiller condenser tubes during annual cleaning of the condensers. Condenser or closed system components may also be opened and available for inspection during other repair or replacement operations. At such times, the Contractor shall be present, and inspect critical components to evaluate a system’s condition. In the event that biological fouling is discovered by these inspections, the

Contractor shall prepare an Out of Compliance Notice Report (Section 7.2.1) and include a recommendation for remedying the condition.

The closed and open systems shall be free of evidence of biological activity that should be controlled by proper water treatment chemistry and control.

If the stated criteria (performance criteria described in Sections 4.4.1 through 4.4.5 below) cannot be met, then the corrective actions described in Section 4.5 shall be undertaken.

1.1.1 Visible Biofilms

The system shall be free of visible biofilms. Flooded surfaces shall be free of visible algae.

Control will be considered adequate through negative analytical results of tests described in

Sections 4.3.2. Biofilm will be determined to be under control by a combination of bacteria testing, negative bacteria response to biocide challenge, and visual inspection.

The Plant Supervisor shall clean the cooling tower basin and visible surfaces a minimum of twice per year.

In the event that visible biofilms persist, the Contractor shall review its microbiological control program and provide a remedial action plan as part of an Out of Compliance Notice Report, as described in the Out of Compliance Notice Report (Section 7.2.1).

1.1.2 Legionella Control

The performance criterion for Legionella species sample analysis results, in all types of systems, is specified in Table 4.3 from laboratory analysis employing the Centers for Disease Control and

Prevention or International Standards ISO 11731.

If Legionella is detected, then the corrective actions described in Section 4.5.1 shall be undertaken.

1.1.3 Total Heterotrophic Bacteria

The following parameters shall not be exceeded in open cooling systems:

Total colony count (defined as the number of colonies developing on nutrient agar after incubation at 35 oC for 2 calendar days, Standard Method SM 9215) shall not exceed

104 cfu/ml in any one test or corrective action shall be taken.

The following parameters shall not be exceeded in closed systems:

Total colony count (defined as the number of colonies developing on nutrient agar after incubation at 35 oC for 2 calendar days, Standard Method SM 9215) shall not exceed

103 cfu/ml in any one test or corrective action shall be taken.

If any of these criteria are not met, the Contractor shall undertake the corrective actions described in 4.5.2 within the time-frames described therein.

1.1.4 Sulfate-Reducing Bacteria

Sulfate-reducing bacteria are primarily sessile bacteria and not expected to be present in the circulating water of any system. If found, the Contractor shall review its microbiological control program and provide a remedial action plan as part of an Out of Compliance Notice Report prepared in accordance with Section 7.2.1.

1.1.5 Iron-Related Bacteria

Many iron-related bacteria are facultative anaerobes and are linked to under-deposit corrosion mechanisms. As such, iron-related bacteria shall be monitored and controlled. If the iron-related bacteria are identified through testing, the Contractor shall review its microbiological control program and provide a remedial action plan as part of an Out of Compliance Notice Report that it shall prepare in accordance with Section 7.2.1.

1.1.6 Free Halogen

A residual between 0.3 and 0.5 mg/l as Cl2 of free halogen shall be achieved in the recirculating water within three calendar days of the contract start date or following a system shutdown. If residual levels of free halogen cannot be achieved within three calendar days, then the corrective action described in Section 4.5.3 shall be taken. This residual shall be maintained at all times.

Control will be considered adequate through under-limit analytical results of tests described in

Sections 4.4.1 through 4.4.3 above.

The 1.0 mg/l elevated level of free halogen for 4 hours weekly shall be confirmed and documented by analytical results.

4.4.7 Nitrite Reducing Bacteria

If nitrite reducing bacteria are identified through testing, the Contractor shall review its corrosion inhibiting and microbiological control programs and provide a remedial action plan as part of an

Out of Compliance Notice Report prepared in accordance with Section 7.2.1.

If the stated criteria (performance criteria described in Sections 4.4.1 through 4.4.3 above) cannot be met, then the corrective actions described in Section 4.5.3 shall be undertaken.

1.2 Corrective Actions

1.2.1 Detected Presence of Legionella

The performance criterion for Legionella species sample analysis results, in all types of systems, is less than one colony forming unit/milliliter (cfu/ml).

Following receipt of a confirmed Legionella count; the Contractor shall perform the actions for cooling towers in Table 4.3 below.

Table 4.3 Legionella Concentrations/Actions

Legionella

Concentration

(cfu/ml)

Action

Less than 1 System under control: Continue with routine maintenance program retest system in accordance with the schedule.

1 to 10 Contractor shall investigate problem and review its Water

Management Program:

Add an extra dose of the non-oxidizing biocide recommended by the chemical suppliers followed in four to six hours by application of oxidizing biocide maintaining a 1.0 mg/l free residual for 4 hours.

Retest the system again after 7 to 14 calendar days.

>10 to 1,000 Contractor shall investigate problem and review its Water

Legionella

Concentration

(cfu/ml)

Action

Management Program:

Immediately perform an on line disinfection of the system.

Retest the system again after 7 to 14 calendar days.

Greater than 1,000 Government will investigate problem and perform an independent review of the Water Management Program. The Contractor shall:

Immediately shut down system and perform offline cleaning and disinfection.

Bring system back on line and ensure dosing equipment is functional.

Retest the system again after 7 to 14 calendars days.

All personnel performing the remediation work on systems that have tested positive for

Legionella bacteria shall use personal protective equipment.

1.2.2 Excessive Total Heterotrophic Bacteria

If either the Contractor or Plant Supervisor detects counts that are greater than 104 but less than

105 cfu/ml, the Contractor shall perform accurate bacterial checks and verify if the water treatment equipment is properly functioning. The Contractor shall verify that the testing was performed correctly and that the biocide applications are occurring according to Section 4.1. The

Contractor shall verify by inventory confirmation that the planned biocide has been applied.

Based on this information, the Contractor shall prepare an Out of Compliance Notice Report as described in Section 7.2.1, and include steps that shall be taken to rectify any application deficiencies.

The Contractor shall review its microbiological contamination control program if the counts remain in excess of 104 for two consecutive weeks and shall provide a remedial action plan as part of an Out of Compliance Notice Report in accordance with Section 7.2.1. The Contractor's review shall consist of documentation of the current control program, any deficiencies in the control equipment, and a crosscheck of system parameters such as system volume and inventory used. The Out of Compliance Notice Report shall be submitted to the Plant Supervisor by the end of the fifth week from the first out-of-specification excursion.

If the counts are greater than 105 cfu/ml, then the system is considered to be out of control and the Contractor shall take immediate action to reduce them as follows: (i) the Contractor shall first check for the proper functioning of the treatment system; (ii) in the event that the high reading cannot be explained by misapplication or misinterpretation of test results, the Contractor shall prepare a plan for remediation and include it in an Out of Compliance Notice Report to be submitted to the Plant Supervisor in accordance with Section 7.2.1, within 48 hours of the initial reading of the test results showing a count greater than 105 cfu/ml.

1.2.3 Residual Free Halogen Not Within Acceptable Range

If the current control settings do not maintain the required control range, the Plant Supervisor will notify the Contractor and the Contractor shall immediately provide instruction for the appropriate corrective action to the Plant Supervisor or, at the Government's sole discretion, the

Plant Supervisor may ask the COTR to require the Contractor to make a site visit to correct the difference within 48 hours of notification.

If the residual of 0.3 to 0.5 mg/l Cl2 of free halogen concentration is not achieved after three calendar days of contract initiation or after three calendar days of any subsequent system start-up and if, after another week of adjustments are equally unsuccessful in achieving the desired range of 0.3- 0.5 mg/l of residual free halogen, then the Contractor shall notify the Plant Supervisor, and complete an Out of Compliance Notice Report in accordance with Section 7.2.1, including a recommended course of action. The Contractor shall perform a complete system disinfection if the Plant Supervisor determines that to be necessary to remedy the situation.

2.0 STEAM BOILER CONTROL PROGRAM

2.1 Chemical Treatments: Oxygen Control

The feedwater shall be treated with a suitable oxygen scavenger to reduce the oxygen content of the feedwater to as low a concentration as practical.

The oxygen scavenger shall be fed separately from the internal treatment chemistry to allow for independent feed to the feedwater system. The oxygen scavenger can also be contained in the internal treatment. The oxygen scavenger should be fed to the exit of the deaerator, or if not available, to the storage section of the deaerator to provide for contact time and good mixing.

The approved oxygen scavenger product name and application concentration range shall be specified in the Program Calculation Sheet, Steam Boiler System sheet(s) that appear in contract

Attachment F-1. The approved product(s) and their application range(s) may not be changed without prior approval of the Government.

2.2 Chemical Treatment: Internal Treatment(s)

The internal boiler water shall be treated with a low precipitating all-polymer treatment to reduce formation of suspended solids in the boiler water and minimize deposition, which can contribute to energy inefficiency or boiler failure. The internal treatment shall include suitable polymeric dispersants and provide for effective alkalinity control.

The makeup water from the well has very low alkalinity and pH (see Appendix 15B), and thus potassium/sodium hydroxide (caustic) is injected into the well water header whenever well water is used as boiler makeup. The rate of caustic shall be adjusted to maintain proper levels of alkalinity in the boiler, as specified in the Program Calculation Sheet, Steam Boiler System.

The internal boiler chemistry shall be maintained in accordance with the “Consensus on

Operating Practices for the Control of Feedwater and Boiler Water Chemistry in Modern

Industrial Boilers,” published by the American Society of Mechanical Engineers (ASME), and all Prince Georges County and Maryland regulations. Table 5.1 quotes the pertinent limits. The boiler system operating requirements are described in the Facility Information Summary, (Exhibit 1).

Table 5.1 ASME Suggested Water Chemistry Limits, Industrial Water Tube Boilers

System Parameter Limit Units

Feedwater Dissolved oxygen <0.007 ppm

Total Iron <0.1 ppm

Total Copper <0.05 ppm

Total Hardness <0.5 ppm pH @ 25C 8.3-10.5

Boiler Water Silica SiO2 <150 ppm

Total alkalinity <1000 ppm

Specific conductance <7000 umhos/cm

The internal boiler water treatment product may contain additional oxygen scavenger and condensate corrosion inhibitors.

The approved internal treatment product name and application concentration range shall be

2.3 Chemical Treatment: Condensate Corrosion Control

The Condensate Corrosion Control Inhibitor is required to minimize the impact of corrosive conditions of condensate to the heat exchange equipment of the facility and the condensate return system.