Purchase of Ammonia Sensors for CC Williams WWTP

Mobile Area Water and
Sewer System
4725 Moffett Road
Mobile, AL 36618-2236
Joyce Sawyer, Buyer II PO Box 180249
(251) 694-3110 Office Mobile, AL 36618-0249
jasawyer@mawss.com
INVITATION FOR BID
May 8, 2026
INVITATION FOR BID NUMBER IFB 26-032
NAME OF BID Purchase of Ammonia Sensors for CC Williams WWTP
MAWSS Purchasing Dept. Bid Box If sending bids by UPS/Fed Ex, deliver to the Warehouse:
East Visitor Entrance 1610 Shelton Beach Rd. Ext., Mobile, AL 36618
BIDS WILL BE RECEIVED AT
4725 Moffett Road with IFB# marked on envelope
Mobile, AL 36618
BID OPENING DATE May 14, 2026
BID CLOSING TIME 10:30 am Central Time
AWARD WILL BE MADE BY Total Cost & Lead Time
CC Williams WWTP
MATERIAL DELIVERED TO 1600 Yeend St.
Mobile, AL 36603
Jed Barbour (251) 378-3513 Email: jbarbour@mawss.com
ADDITIONAL INFORMATION CONTACT
Michael Ponder (251) 721-2850 Email: mjponder@mawss.com
APPLICABLE SDP POLICY None
Sealed bids must be in the Purchasing Department no later than the time specified in order to be considered. Submissions
received after the deadline will not be considered. Envelopes must bear the name of the supplier, company address and the
words "IFB 26-032 Ammonia Sensors Purchase" or "IFB 26-032 NO QUOTE." Facsimile or email bids will not be accepted.
All bids must be submitted on the attached forms, or your bid will be disqualified. Bidder shall furnish all the information
required by the solicitation. The bidder's name must be typed or printed on the bid sheet and signed by the bidder or
appropriate authorized executive officer of the bidder's company. Bidders must initial any changes or erasures. Bidders should
retain a copy of bids for their records.
Bidders shall acknowledge receipt of all addenda to this solicitation by signing and returning each addendum or by identifying
the addendum number and the date on the bid form. Failure to acknowledge receipt of any addendum by a bidder will result
in rejection of the bid if MAWSS determines that the addendum contains information that materially changes the requirements.
All bids shall be quoted FOB Destination, freight prepaid with no additional charges. Unless otherwise specified in the bid, all
prices will be on a firm-fixed price basis and are not subject to adjustments based on costs incurred. MAWSS reserves the right
to reject any or all bids submitted, to waive any informality in any bid or in the bid process, or to terminate the bid process at
any time, if deemed by MAWSS to be in MAWSS's best interest.
A Purchase Order and this "Invitation for Bid" with "Specifications," "Conditions," "Bid Form," signed by the successful bidder's
authorized representative, and all attached drawings and other documents furnished by MAWSS to the bidders with the
Invitation for Bid in order to illustrate the contract requirements, will constitute a contract for the goods and/or services to be
purchased.
IFB 26-032 Ammonia Sensors Purchase Page 1 of 14

IFB 26-032 AMMONIA SENSORS PURCHASE
CONDITIONS
The Board of Water and Sewer Commissioners of the City of Mobile will accept bids for the Ammonia Sensors Purchase in our
Purchasing Department Bid Box located at the East Visitor Entrance at 4725 Moffett Road, Mobile, AL. 36618 no later than
10:30 a.m. local time on May 14, 2026. Bids will be opened immediately after bid closing time in the Operations Center Board
room located at the East Visitor Entrance. Award will be by Total Cost & Lead Time. The bidder offers and agrees, if this bid is
accepted, to furnish the items as defined in the specifications for the unit price set opposite each item. Pricing shall be FOB
Mobile, Alabama. All items shall be delivered to CC Williams WWTP located at 1600 Yeend St., Mobile, AL 36603, or to the
job site as needed. The bidder shall state the expected length of delivery time on the Bid Form.
Bidder understands and agrees that manufacturer and part numbers are provided for descriptive purposes only. Items of equal
or better quality will be considered but must be approved by MAWSS in writing. Upon delivery, if the quality, durability or
performance of any product represented as equal or better is determined by MAWSS to be unsatisfactory, MAWSS will require
a suitable substitute or will require that the originally specified item be delivered, at the unit price originally offered by bidder.
No substitution for items to be provided pursuant to this contract shall be permitted during the contract period without the
express written consent of MAWSS. All items provided shall be for commercial use and for the purposes reflected in the
contract documents.
No bid on closed out or discontinued item(s) will be accepted. Item(s) that have a determinable shelf life must be disclosed at
the time of bid submittal. Bidder understands that his/her bid shall be good and may not be withdrawn for a period of sixty
(60) calendar days after the scheduled closing time for receiving bids.
Bidder understands and agrees that quantities will be purchased by MAWSS on an "as needed" basis to replenish inventory.
MAWSS shall not be committed to the purchase of a pre-established minimum quantity for any one item.
A bidder may not modify its bid after bid opening. Errors in the extension of unit prices stated in a bid or in multiplication,
division, addition or subtraction in a bid may be corrected by the MAWSS Purchasing Buyer prior to award. In such cases, unit
prices shall not be changed.
It is the responsibility of the bidder to determine prior to the bid opening whether any amendment, additions, deletions or
changes of any type have been made to this Invitation for Bid, Conditions, Specifications, Bid Form or any other bid documents.
Bid documents and any amendments made to this bid will be posted on our website at www.mawss.com.
Invoicing Requirements: MAWSS requires additional information for all work performed and services provided. On the vendor's
invoice for payment should be a detailed listing of work performed, services provided, dates completed, locations involved,
and any other pertinent information needed to verify the work and/or services were completed in accordance to the bid specs.
This additional information can be supplied in the form of detailed invoices, work orders, checklists or any other documents
used to track the work performed or services provided but details must be included on the actual invoice. A copy of the invoice
and these additional details must be sent to the "ADDITIONAL INFORMATION CONTACT" found on Page 1 of the bid documents
and a copy emailed to Accounts Payable at AcctsPayable@mawss.com.
END OF CONDITIONS
IFB 26-032 Ammonia Sensors Purchase Page 2 of 14

IFB 26-032 AMMONIA SENSORS PURCHASE
SPECIFICATIONS
WASTEWATER ANALYSIS INSTRUMENT CONTROLLER & PROBE SPECIFICATIONS
GENERAL
The purpose of this bid is to purchase:
1. Three (3) instrument controllers capable of transmitting sensor data from multiple water quality
parameters
2. Three (3) sensors for continuous monitoring of ammonium nitrogen and nitrate nitrogen in
wastewater treatment.
3. Two (2) high output air compressors capable of cleaning sensor equipment.
4. Items necessary for mounting/installation of the instrumentation.
Note: Potential bidders are encouraged to make a site visit to fully understand the requirements of a
successful implementation.
PART 1 - INSTRUMENT CONTROLLER GENERAL
1. A dual channel water quality sensor transmitter with a local user interface AND the ability to
access sensor data remotely through a browser enabled device.
2. Scope:
A. Provide labor, material, equipment, related services, and supervision to install and operate
the controller to drawings and manufacturer's specifications.
3. Alternates:
A. Parameter-specific controllers that do not allow changing parameter configurations in the
field are unacceptable.
B. Controllers or transmitters without the possibility to access data through an internet
browser enabled device and cannot present real-time instrument diagnostics are not
acceptable.
System Descriptions
1. Design requirements
A. Includes capability to actively monitor all internal components and present diagnostics on
the overall health of connected sensors and time to next required maintenance, reducing
user risk.
i. Ability to see and be notified of upcoming and past due maintenance.
B. Includes capability to provide real-time alerts when sensor issues occur with built in
workflows with step-by-step guidance to perform calibration and maintenance tasks,
reducing user risk.
C. Includes ability for cellular network coverage OR Wi-Fi connection OR a LAN
connection.
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D. Supports advanced communication protocols, including Profibus DPV1, Modbus TCP/IP,
Profinet IO, and Ethernet IP.
E. Provides capability to view all connected plant measurements, alerts, calibration, and
maintenance status in real time on any internet browser capable device.
i. Connects with overall data system for real time graphics of both online and
laboratory data for a full picture of functional plant operational capability.
F. Controller designed to be used in indoor or outdoor locations.
2. Performance Requirements
A. The controller accepts digital sensors in any combination to measure the following water
quality parameters:
i. pH/ORP
ii. Conductivity
iii. Dissolved Oxygen
iv. UV Organics
v. Sludge level
vi. Ammonium
vii. Ammonia
viii. Nitrate
ix. Combination of Ammonium and Nitrate
x. Total suspended solids
xi. Orthophosphate
xii. Turbidity
xiii. Free/total Chlorine
xiv. Combination Chlorine HOCl /Chlorine+Acid / Total free chlorine
xv. Ozone in water
xvi. Chlorine Dioxide
xvii. Oil in Water
xviii. Nitrite
3. Environmental Requirements
A. Operational Criteria
i. Operating Temperature: -20 to 45 degreesC (-4 to 113 degreesF)
ii. Storage temperature: -20 to 70 degreesC (-4 to 158 degreesF)
iii. Relative humidity: 0 to 95%, non-condensing
iv. Altitude 3000m (6,562 ft.)
4. Certifications
A. EMC: CE approved (with all sensor types). Listed for use in general locations to UL and
CSA safety standards by ETL (with all sensor types).
B. Safety: General Purpose UL/CSA 61010-1 with cETLus safety mark
C. Possibility for Hazardous Locations Use: Class 1 Div 2
IFB 26-027 HVAC Replacements for Park Forest Page 4 of 14

5. Warranty
A. Warranted for 1 year from date of shipment from manufacturer defects.
6. Unscheduled Maintenance
A. Clean controller face
B. Calibrate mA output signals
PART 2 - INSTRUMENT CONTROLLER PRODUCTS
1. Equipment shall be:
A. Hach Company, Loveland, Colorado and Hach Lange GmbH, Berlin, Germany
i. SC4500 Controller
B. Or Approved Equivalent
2. Manufactured Unit
A. Microprocessor-based sensor controller.
B. Change digital sensors connected to the controller by unplugging and plugging in sensors
as necessary.
C. Modules for connection of Analogue sensors for pH, ORP or Conductivity
D. The controller is available with the following power requirements:
i. AC powered: 100-240 VAC 10%, 50/60 Hz; 1 A (28 W sensor load)
ii. DC powered: 24 VDC +15% -20%; 2.5 A (20 W sensor load)
E. The controller uses a menu-driven operation system.
F. The controller is equipped with a real-time clock.
G. The controller is equipped with two security levels.
H. The controller shall have worded operation menus in 24 languages.
I. The controller is equipped with a USB reader for data download and controller software
upload.
J. High voltage:
i. Two relays (SPDT);
ii. Wire gauge: 0.75 to 1.5 mm2 (18 to 16 AWG)
iii. AC controller:
Maximum switching voltage: 100-240 VAC
Maximum switching current: 5 A Resistive/1 A Pilot Duty
Maximum switching power: 1200 VA Resistive/360 VA Pilot
iv. Duty DC controller
Maximum switching voltage: 30 VAC or 42 VDC
Maximum switching current: 4 A Resistive/1 A Pilot Duty
Maximum switching power: 125 W Resistive/28 W Pilot Duty
K. Five analogs 0/4-20 mA outputs are provided with a maximum impedance of 500 ohms.
i. The controller can be equipped with five 4-20 mA outputs with a maximum
impedance of 500 ohms.
IFB 26-027 HVAC Replacements for Park Forest Page 5 of 14

ii. The following can be programmed:
1. Alarms:
a. High and Low alarm point
b. High and Low alarm point deadband
c. On and Off delay
2. Controls
a. Linear
b. PID
L. The controller can be equipped with the following forms of communication:
i. Profibus DP
ii. Modbus TCP/IP
iii. Profinet (ODVA certified)
iv. Ethernet IP (ODVA certified)
M. The controller can host one of the compatible RTC modules
N. All user settings of the controller are retained for 10 years in flash memory.
O. The controller is equipped with a system check for:
i. Motherboard temperature
ii. Field auto-test
3. Equipment
A. Materials
i. Housing: polycarbonate, aluminum (powder coated), and stainless-steel Metal
enclosure with a corrosion-resistant finish
ii. Rating: UL50E type 4X, IEC/EN 60529-IP 66, NEMA 250 type 4X
B. Conduit openings: 0.5 in. NPT
PART 3 - INSTRUMENT PROBE GENERAL
1. Sensor for continuous monitoring of ammonium nitrogen and nitrate nitrogen in one probe in
wastewater treatment.
2. Includes the capability to remotely monitor sensors on any browser-enabled device and present
diagnostics on the overall health of the measurements (on Predictive Diagnostics-enabled sensors),
as well as upcoming and required maintenance - reducing user risk and downtime. It includes the
capability to connect to a laboratory spectrophotometer to correct process measurements based on
lab samples, without having to remove the process sensor from the water.
3. Measurement Procedures
A. The method of measuring ammonium nitrogen and nitrate nitrogen is by ion-selective
electrodes (ISE).
i. A differential pH electrode is used as the reference.
ii. A potassium ISE is used to correct the ammonium value for the presence of
potassium ion.
iii. A chloride ISE is used to correct the nitrate value for the presence of chloride ion.
IFB 26-027 HVAC Replacements for Park Forest Page 6 of 14

4. Alternates
A. Other sensors that do not use a differential pH reference electrode are not acceptable.
B. Other sensors that do not use both potassium ISE to correct the ammonium value and
chloride ISE to correct the nitrate value are not acceptable.
C. Other instruments that do not have predictive diagnostic capabilities are unacceptable
5. System Description
A. Performance Requirements
i. Measurement range ammonium: 0.2 to 1000 mg/L NH4-N
ii. Measurement range nitrate: 0.2 to 1000 mg/L NO3-N
iii. Accuracy: 5% of measured value 0.2 mg/L (with standard solution)
iv. Detection limit: 0.2 mg/L
v. Response time: less than 3 minutes (T90)
vi. When connected to a multi-parameter digital controller the overall status of the
instrument performance is displayed as a percentage value via a measurement
indicator
vii. When connected to a multi-parameter digital controller the overall time remaining
until maintenance tasks are due is displayed in days
6. Certifications
A. CE approved
7. Environmental Requirements
A. Operational Criteria
B. Operating temperature -20 to 45 degreesC (-4 to 114 degreesF)
C. Sample temperature: 2 to 40 degreesC (35 to 104 degreesF)
D. Sample pH: 5 to 9
E. Sensor immersion depth: 0.3 to 3.0 meters (1 to 10 feet) maximum
F. Sample pressure: 0.3 bar (4.4 psi) maximum
8. Warranty
A. The product shall include a one-year warranty from date of shipment covering diagnosis,
parts, freight, and labor; excluding wear parts.
9. Maintenance Service
A. Scheduled maintenance:
i. 1. Monthly: visual inspection, if necessary, clean with brush and clear water
ii. Bi-annually: replace calibrated sensor cartridge
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PART 4 - INSTRUMENT PROBE PRODUCTS
1. Manufacturer
A. Hach Company, Loveland, CO
i. 1. AN-ISE sc Ammonium and Nitrate Combination Sensor
B. Or Approved Equivalent
2. Manufactured Unit
A. The AN-ISE sc Ammonium and Nitrate Combination Sensor consists of a digital sensor
with integrated, replaceable sensor cartridge.
B. The integrated sensor cartridge includes ammonium ISE, nitrate ISE, differential pH
electrode, potassium ISE, chloride ISE, and temperature sensor.
3. Equipment
A. The sensor is designed to connect to a universal digital controller.
B. The sensor cartridge is factory calibrated with all electrodes individually calibrated and
also calibrated to each other.
C. The sensor does not require sample conditioning.
D. The sensor can perform one- or two-point inline matrix corrections to adapt it to a
wastewater matrix.
E. The sensor is corrosion resistant and fully immersible.
4. Components
A. Standard equipment:
i. Probe:
1. stainless steel (1.4571)
2. Ends: ASA + PC
B. Dimensions: 12.6 x 3.3 inches (320 mm x 84.5 mm)
C. Weight: 5.3 lbs. ( 2.4 kg)
5. Accessories
A. Digital controller
B. Cables and power cord
C. Mounting kit
i. Rail Mount
ii. Chain Mount
iii. Rim Mount
D. Cleaning unit
i. High Output Air Blast Cleaning Compressor (See Part 5)
IFB 26-027 HVAC Replacements for Park Forest Page 8 of 14

Part 5 - High Output Air Blast Cleaning Compressor
1. High Output Air Blast (HOAB). Compressed air will be provided to make it possible to clean a
probe. A probe specific cleaning head needs to be used to fit with the specific probe involved.
Probe specific cleaning head is not a part of the HOAB.
2. Measurement Procedures
A. Compressed air generated from a compressor will be let to a cleaning device (cleaning
head). The design of the probe specific cleaning head makes sure that the surface of the
measuring part of the probe remains clean.
3. Alternates
A. Manual cleaning of the measuring part of the probe is not acceptable
4. System Description
A. Performance Requirements
i. Air pressure (at compressor outlet): 115VAC 3.1 bar (45psi) / 230VAC 2.8 bar (40
psi)
ii. Air flow (at compressor outlet): 115VAC 2.1 m3/hour / 230VAC 1.8m3/hour
5. Certifications
A. UL, CSA, cETLus, CE
6. Environmental Requirements
A. Operational Criteria
i. Operating temperature -20 to 50 degreesC (-4 to 122 degreesF) 95% rel. humidity non-
considering
7. Warranty
A. The product shall include a one-year warranty from date of shipment covering diagnosis,
parts, freight, and labor; excluding wear parts.
8. Maintenance Service
A. Scheduled maintenance:
i. Weekly / Monthly: visual inspection, if necessary, cleaning of the air intake,
depending on location.
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Part 6 - High Output Air Blast Cleaning Compressor Products
1. Manufacturer
A. Hach Company, Loveland, CO
i. HOAB, High Output Air Blast system
B. Approved Equivalent
2. Manufactured Unit
A. The HOAB consists of a non-metallic cabinet (enclosure) including a compressor, which
needs to be installed along the probe equipped with a cleaning head at the basin and
approx. 9m (27ft) air hose.
3. Equipment
A. The HOAB is a stand-alone system (AC powered), including a controller relay fuse (T,
0.25 A, 250 V).
B. The enclosure is made of Polycarbonate and is suitable for outdoor installation.
C. The air hose is suitable for outdoor installation.
4. Components
A. Standard equipment:
i. Control unit
1. Polycarbonate
ii. Air hose
1. Tygon style, braided
iii. Mounting accessories
1. Stainless Steel
iv. Manual
5. Dimensions:
A. Control unit: (W x H x D) 351.6 x 186.9 x 409.7 mm (13.84 x 7.36 x 16.13 inches)
B. Weight:
i. Control unit: 11.2 kg/24.7 lbs
6. Accessories
A. Probe specific cleaning head (1 each)
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