191BWC26R0018_Amendment_0002_Continuation.pdf

UNITED STATES SECTION

INTERNATIONAL BOUNDARY AND WATER COMMISSION

AMENDMENT 0002 TO SOLICITATION 191BWC26R0018

Nogales Instrumentation, Hach Sensor and Controller Upgrade

Solicitation Number 191BWC26R0018

Amendment Number 0002

Amendment Date September 9, 2026

Offer Due Date and Time September 18, 2026, at 3:00 PM Mountain Time

Purpose of Amendment

1. Provide official responses to contractor questions concerning connection of the required sensors to the existing SCADA system.

2. Revise Performance Work Statement Section 1.4 to incorporate the additional SCADA integration, wired infrastructure, radio telemetry, and radio security requirements identified by USIBWC.

3. Incorporate the revised Performance Work Statement titled Combined PWS and Plant Diagram, Updated

September 8, 2026. The revised Performance Work Statement replaces the previously posted version for purposes of proposal preparation.

4. The offer due date remains September 18, 2026, at 3:00 PM Mountain Time.

5. All other solicitation terms and conditions remain unchanged.

Revised Performance Work Statement, Section 1.4 The revised Performance Work Statement adds the following requirements following the RAS Line requirements in Section 1.4:

1. Offerors shall provide pricing for both wired infrastructure installation and radio telemetry installation.

2. The system must be fully integrated into the existing SCADA system, including updates and operations through the main unit and not through a separate system.

3. USIBWC Information Management Division recommends that Operations and Maintenance have a

SCADA expert onsite to support smooth integration into the existing system.

4. Any radio system must be point to point, FIPS compliant, TAA compliant, and have no connection to outside networks or systems.

5. LDO probes are connected to SCADA to control bioreactor blowers. All other sensors are to be connected to SCADA for historian and real time monitoring purposes.

Contractor Questions and Official USIBWC Responses

Question 1 What is intended by “connect the sensors to SCADA”? Does this mean reconnect only the sensors already connected to SCADA, connect all new sensors to SCADA, and does connection include wiring to the SCADA cabinet or integration into the existing SCADA programming?

USIBWC Response All required sensors are to be connected so their data may be read at the SCADA room. LDO probes must be integrated into SCADA programming to control the bioreactor blower valves. Other sensor data, including temperature, pH, ammonia, total suspended solids, and similar process data, must be available for display, historian, and real time monitoring.

Question 2 If all sensors must be connected to SCADA, is radio telemetry an acceptable communication method, or must the sensors be hardwired?

USIBWC Response Radio telemetry is acceptable. Offerors shall provide pricing for both wired infrastructure installation and radio telemetry installation. The system must be fully integrated into the existing SCADA system. Any radio system must be point to point, FIPS compliant, TAA compliant, and have no connection to outside networks or systems.

Question 3 What is intended by the requirement to test sensors to meet the plant environmental control requirements? Are the sensor readings intended to control plant processes through SCADA?

USIBWC Response Currently, only the dissolved oxygen probes are connected to SCADA to control blowers in the aeration basins. All other sensors must be connected to SCADA for historian and real time monitoring and will not directly control plant processes through SCADA.

Offeror Action Offerors shall review the revised Performance Work Statement and incorporate Amendment 0002 into their proposals. Offerors shall acknowledge Amendment 0002 with their offer. Proposal submission remains through the USIBWC secure Microsoft SharePoint portal in accordance with the solicitation.

END OF AMENDMENT 0002