PE Firm Registration No. 1151 PG Firm Registration No. 50103 RPLS Firm Registration No. 10011900

July 15, 2020

ACTON MUNICIPAL UTILITY DISTRICT GRANBURY, TEXAS

WASTEWATER TREATMENT PLANT NO. 1 IMPROVEMENTS

Addendum No. 1 Attention is called to the following modifications to the referenced Plans, Specification and Contract Documents for the above referenced project. The Acton Municipal Utility District (District) will receive bid forms and bid bonds for Wastewater Treatment Plant No. 1 Improvements at the District’s office, located at 6420 Lusk Branch Court, Granbury, TX 76049, until 2:00 p.m., local time on Tuesday, July 28, 2020, at which time the bids received will be publicly opened and read. We hereby modify the documents as follows: CONTRACT:

1. The Acton Municipal Utility District (District) will receive bid forms and bid bonds for Wastewater Treatment Plant No. 1 Improvements at the District’s office, located at 6420 Lusk Branch Court, Granbury, TX 76049, until 2:00 p.m., local time on Tuesday, July 28, 2020, at which time the bids received will be publicly opened and read. Due to current Covid-19 social distancing requirements, prospective bidders shall not remain inside the Acton MUD office after submitting their bid; instead, after submitting a bid, a prospective bidder shall return to their vehicle outside the Acton MUD office until the bid opening time of 2:00 pm, at which time one representative of a prospective bidder’s company may re-enter the Acton MUD building to attend the bid opening in the Acton MUD board room. Bids will be publicly opened and read aloud immediately thereafter at same location. Any interested parties attending the bid opening, while within the Acton MUD office and/or Acton MUD board room, shall maintain social distancing requirements and shall wear a mask or face covering at all times, in addition to any other protective measures set in place by the State of Texas at the time of the bid opening. The total number of attendees at the bid opening shall be limited to 10 people or less, pending any further requirement changes set forth by the State of Texas at the time of the bid opening. Following calculation verification, the opened bids shall be tabulated and posted on the project webpage at www.civcastusa.com for any interested parties who want to see the bid information without attending the bid opening in person. Following calculation verification, the apparent low bidder will be contacted immediately by the Project Engineer.

Page 2

DRAWINGS:

1. DELETE Sheet 02D-11 and REPLACE with the attached revised Sheet. The sheet has been revised for clarifications on the mechanical screen and weir and slide gates at the screening structure.

2. DELETE Sheet 02D-12 and REPLACE with the attached revised Sheet. The sheet has been revised for clarifications on the mechanical screen and weir and slide gates at the screening structure.

3. DELETE Sheet 08Y-210 and REPLACE with the attached revised Sheet. The sheet has been revised for clarifications on the mechanical screen and weir and slide gates at the screening structure.

4. DELETE Sheet 01E-01 and REPLACE with the attached revised Sheet. The sheet has been revised to clarify site electrical adjustments.

5. DELETE Sheet 02E-01 and REPLACE with the attached revised Sheet. The sheet has been revised for clarifications on the mechanical screen and weir and slide gates at the screening structure.

6. DELETE Sheet 04E-01 and REPLACE with the attached revised Sheet. The sheet has been revised to remote motor operators for removed drain valves.

7. DELETE Sheet 07E-01 and REPLACE with the attached revised Sheet. The sheet has been revised to clarify panelboard adjustments.

8. DELETE Sheet 07E-03 and REPLACE with the attached revised Sheet. The sheet has been revised

to clarify one line diagram adjustments.

9. DELETE Sheet 07E-04 and REPLACE with the attached revised Sheet. The sheet has been revised to clarify one line diagram adjustments.

10. DELETE Sheet 07E-09 and REPLACE with the attached revised Sheet. The sheet has been revised

to clarify instrumentation one line diagram adjustments.

11. DELETE Sheet 07E-16 and REPLACE with the attached revised Sheet. The sheet has been revised to clarify duct bank sections.

12. DELETE Sheet 07E-17 and REPLACE with the attached revised Sheet. The sheet has been revised

to clarify electrical conduit schedules.

13. DELETE Sheet 07E-18 and REPLACE with the attached revised Sheet. The sheet has been revised to clarify electrical conduit schedules.

SPECIFICATIONS:

1. Section 11075 “Mechanical Coarse Screen”: DELETE the existing specification and replace with a new mechanical screen specification included in this addendum.

Page 3

2. Section 11260 “Chlorination Equipment”, 2.1.A: ADD the following approved manufacturers to the list:

a. Regal.

3. Section 11401 “Biofiltration System”, 2.1.A: ADD the following approved manufacturers to the list: a. ECS.

4. Section 15068 “FRP Pipe”: ADD the specification included in this addendum.

5. Section 16210 “Diesel Engine Generator and Controls”: DELETE the existing specification and

replace with a new generator specification included in this addendum.

CLARIFICATIONS:

1. Coatings:

a. Coatings are required for the internal wetted surfaces for all new structures, not just the new screening and grit removal structures.

This addendum consists of forty-five (45) pages and becomes a part of the referenced plans, specifications and contract documents and shall be acknowledged by the bidder and attached to the bid packet submitted.

By Joshua L. Berryhill, P.E. #100323 Project Engineer

7/15/2020

102D-12

2'-0

"2'

-0"

1'-0

"

302

D-1

2

1'-0

"

3'-0"

202D-12

PLANSCALE: 3/8" = 1'-0"

2'-6

"

2'-6"

5'-0

"

PVC

DIP

PVCDIP

PVCDIP

5'-0"

5'-0"

1" MANUALBAR SCREEN(02-SCR-1111)

209D-10

36" x 24" 316SSSLIDE GATE,TYP. (02-SG-1111)

24" x 24" 3161SSSLIDE GATE, TYP.(02-SG-1121)

209D-10

REFER TO STRUCTURAL FORMOUNTING REQUIREMENTS

DIVIDER WALL(REFER TOSTRUCTURAL)

LEVEL SENSOR02-LE-1112

LEVEL SENSOR02-LE-1111

NTO GRITREMOVAL SYSTEM(REFER TO 01C-31FOR CONTINUATION)

16-RWW-PVC

TO PRE-EQ BASIN No. 2(REFER TO 01C-31 FORCONTINUATION)

TO PRE-EQ BASIN No. 1(REFER TO 01C-31 FORCONTINUATION)

12-RWW-PVC

15-RWW-PVC

209D-10

36" x 24" 316SSSLIDE GATE, TYP.(02-SG-1112)

6-INF-PVC

6-RCY-PVC

12-INF-PVC

209D-10

36" x 24" 316SSSLIDE GATE, TYP.(02-SG-1122)

NEW 0.25 INC, TYP.SCREEN(02-MS-1111)

48"SIDEWALK

ALUMINUMDIAMOND CHECKEDPLATE (REFER TOSTRUCTURAL)

FROM DRAIN RECYCLEPUMP STATION

FROM OFFSITE LIFTSTATIONS (REFER

TO 01C-31 FORCONTINUATION)

4-FA-FRP

PVC

GALV

1 1/4-NPW-PVC

409D-01

PIPE SUPPORTTYP.

409C-04

HOSEBIBB

TO ODOR CONTROL SYSTEM(FOR CONTINUATION REFERTO SHEET 01C-31)

109D-06

WALL PIPE,TYP. PE x FLRELOCATED

SCREEN CONTROLPANEL (REFER TOELECTRICAL)

FLOW

FLOW

HANDRAIL

109D-06

WALL PIPE,TYP. PE x PE

SCREENING DUMPSTER(PROVIDED BY OWNER)

30" x 40" 316SSMOTOR ACTUATEDSLIDE GATE, TYP.

24" x 18" 316SSADJUSTABLE WEIRGATE , TYP.(02-WG-1131, 02-WG-1132)

2' x 2' DRAINPLATE

6"

2'-0

"

2

02D-11

3/8" = 1'-0"

SCREENING SYSTEMMODIFICATION PLAN

A

REVISIONNO.

1DATE

2

B C D

4

3

5

A B C D

E F

J.B.H. / S.A.E.

DRAWN BY

CHECKED BY

DESIGNED BY

G

06/12/2020

DATE

SCALE

H I

1

2

E F G

3

4

H I

5

BAR IS ONE INCH ONORIGINAL DRAWING

IF NOT ONE INCH ONTHIS SHEET. ADJUST

SCALES ACCORDINGLY.

0 1

ACTON MUNICIPAL UTILITY DISTRICTTWDB CWSRF - WWTP NO. 1 IMPROVEMENTS

ENVIRONMENTAL AND CIVIL ENGINEERING402 Cedar Street325-698-5560 PE Firm Registration No. 1151

Abilene, Texas 79601

ENPROTEC/HIBBS & TODD, INC.

PG Firm Registration No. 50103RPLS Firm Registration No. 10011900

16-6633

SHEET No.

SEQUENCE No.

PROJECT NO.:

OF 184

J.L.B.

J.L.B.

06/12/2020

37

NOTES:

1. FOR ADDITIONAL NOTES, REFER TO SHEET 00G-06.

2. ALL ITEMS ON THIS SHEET ARE NEW UNLESS OTHERWISE INDICATED.CONTACTOR TO FIELD VERIFY ALL EXISTING PIPING, STRUCTURES, ANDUTILITIES, PRIOR TO CONSTRUCTION. CONTRACTOR TO NOTIFY ENGINEERIMMEDIATELY OF ANY DEVIATIONS.

3. VALVES UNDER 1-INCH WILL NOT BE SHOWN FOR CLARITY. REFER TOP&ID SCHEMATICS FOR ADDITIONAL INFORMATION. NOT ALL COMPONENTSPROVIDED BY SCREEN MANUFACTURER MAY BE SHOWN FOR CLARITY. ITIS THE CONTRACTOR'S RESPONSIBILITY TO REVIEW THE EQUIPMENT P&IDS.

4. REFER TO SPECIFICATION 11075 FOR ADDITIONAL DETAIL ON THEMECHANICAL SCREENING EQUIPMENT REQUIREMENTS. SCREENING LAYOUTBASIS IS LAKESIDE FPFS SCREEN.

5. REFER TO SHEET 08Y-210 FOR THE P&ID FOR THE MECHANICAL SCREENINGSYSTEM.

1 ADDENDUM NO. 2 07/13/2020

SECTIONSCALE: 3/8" = 1'-0"

202D-11

28'-8"

209D-10

24"x24" 316SSSLIDE GATE, TYP.(02-SG-1122)

PERFORATED 316SSPLATE DRAIN PANFOR MANUAL SCREEN

ALUMINUM DIAMONDCHECKED PLATE, TYP(REFER TO STRUCTURAL)

F.F. ELEV. 748.00

TOP OF WALLELEV. 754.00

6'-0

"

7'-0 1/4"

1'-0"

3'-0" 3'-0"

SLIDE GATENOT SHOWNFOR CLARITY

2'-0"

INV. EL. 749.00

6-INF-DI

209D-10

24"x24" 316SSSLIDE GATE, TYP.(02-SG-1121)

24"x18" 316SSADJUSTABLEWEIR GATE, TYP.(02-WG-1132)

709C-04

CONCRETEENCASEMENT

TO PRE. EQ. No. 1(FOR CONTINUATION

REFER TO SHEET01C-31)

109D-06

WALL PIPE,PE x PE TYP.

FLOW

1" 316SS COARSEMANUAL BARSCREEN (02-SCR-1111)

16-RWW-DI

6" MJ 90°BEND, TYP.

6-RCY-DIPE x PE LENGTHAS REQUIRED

6" FL 90°BEND, TYP.

109D-06

WALL PIPE,PE x MJ TYP.

FROM DRAIN RECYCLEPUMP STATION

SECTIONSCALE: 3/8" = 1'-0"

1-

1'-0"

209D-10

3'-0"

209D-10

709C-04

109D-06

109D-06

45°

R7'-0 1/2"

TOP OF WALLELEV. 754.00

36"x24" 316SSSLIDE GATE, TYP.(02-SG-1111)

36"x24" 316SSSLIDE GATE, TYP.(02-SG-1112)

24"x18" 316SSADJUSTABLE WEIRGATE, TYP. (02-WG-1131)

TO PRE. EQ. BASIN No. 2(FOR CONTINUATION

REFER TO SHEET 01C-31)

CONCRETEENCASEMENT

WALL PIPE,TYP. PE x PE

LEVELSENSOR02-LE-1112

LEVELSENSOR02-LE-1111

FLOW

F.F. ELEV. 748.00

INV. EL. 749.00

F.G. EL. 743.50

12" MJ 90°BEND, TYP.

F.G. EL. 743.50

WALL PIPE,TYP. PE x PE

12" MJ 90°BEND, TYP.

12" MJ 90°BEND, TYP.

12-INF-DI PE x PELENGTH AS REQUIRED

FROM OFFSITE LIFT STATIONS(FOR CONTINUATION REFERTO SHEET 01C-31)

DEWATERING CHAMBER

TUBE HEATER

SOLENOID VALVES

BAGGERATTACHMENT

ALUMINUMDIAMONDCHECKED PLATE(REFER TOSTRUCTURAL)

6-INF-DI

4-FA-FRP INV.ELEV. 752.00

PEAK WSE: 751.00DESIGN WSE: 749.14PEAK WSE: 751.00

DESIGN WSE: 748.64

309C-01

48"SIDEWALK

PEAK WSE: 751.50DESIGN WSE: 749.14PEAK WSE: 751.00

DESIGN WSE: 748.64

NEW 0.25 INCHSCREEN (02-MS-1111)

HANDRAIL

REFER TOSTRUCTURAL FOREQUIPMENT MOUNTINGREQUIREMENTS

309C-01

48" SIDEWALK,TYP.

209C-07

THRUSTBLOCK, TYP.

12-RWW-DIPE x PE LENGTHAS REQUIRED

12-RWW-DIPE x PE LENGTHAS REQUIRED

1'-0"

F.G. EL. 743.50 F.G. EL. 743.50

309C-01

48"SIDEWALK

309C-01

48" SIDEWALK,TYP.

209C-07

THRUSTBLOCK, TYP.

1'-0"1'-0"

REINFORCED BACKUPMANUAL SCREEN (REFERTO 05500 SPECIFICATION)

15-RWW-DIPE x PE LENGTHAS REQUIRED

16-RWW-DIPE x PE LENGTHAS REQUIRED

INTERNALDIVIDER

WALL

C.L. EL. 740.50

CL. ELEV. 738.33 CL. ELEV. 738.33

0'-6"

2'-0

"

0'-6"

2'-0

"

2

2

SECTIONSCALE: 1/2" = 1'-0"

302D-11

F.F. EL. 748.00

TOP OF WALLELEV. 754.00

2'-0"2'-0"

ALUMINUM DIAMONDCHECKED PLATE, TYP(REFER TO STRUCTURAL)

1" MANUALSCREEN(02-SCR-1111)

NEW0.25" SPIRALSCREEN(02-MS-1111)

6'-0

"

F.G. EL. 743.50SIDEWALK

409D-01

PIPESUPPORT,TYP.

1 1/4-NPW-GALV

HANDRAIL

2

A

REVISIONNO.

1DATE

2

B C D

4

3

5

A B C D

E F

J.B.H. / S.A.E.

DRAWN BY

CHECKED BY

DESIGNED BY

G

06/12/2020

DATE

SCALE

H I

1

2

E F G

3

4

H I

5

BAR IS ONE INCH ONORIGINAL DRAWING

IF NOT ONE INCH ONTHIS SHEET. ADJUST

SCALES ACCORDINGLY.

0 1

ACTON MUNICIPAL UTILITY DISTRICTTWDB CWSRF - WWTP NO. 1 IMPROVEMENTS

ENVIRONMENTAL AND CIVIL ENGINEERING402 Cedar Street325-698-5560 PE Firm Registration No. 1151

Abilene, Texas 79601

ENPROTEC/HIBBS & TODD, INC.

PG Firm Registration No. 50103RPLS Firm Registration No. 10011900

16-6633

SHEET No.

SEQUENCE No.

PROJECT NO.:

OF 184

J.L.B.

J.L.B.

06/12/2020

02D-12

AS NOTED

SCREENING SYSTEMMODIFICATION SECTIONS

38

1 ADDENDUM NO. 2 07/13/2020

6" FM FROM NELIFT STATION

8" FM FROMCOLLECTION

SYSTEM

1-1/4"-NPW 1"-NPW

1"-NPW

SW

SW

FROM PLANTWATER SYSTEM

1-1/4"x1"

1-1/

4"x1

"

LIT

LELE LIT

M

LY

LYHSI

HOA

YA

GEN

ERAL

ALAR

M

LOCAL CONTROL PANEL LEVEL

SCADA DISPLAY LEVEL

08Y-610

08Y-220 TO EQ BASINSNo.2 SYSTEM

08Y-220 TO EQ BASINNo. 1 SYSTEM

08Y-230 TO GRITREMOVAL SYSTEM(BID ALTERNATIVE)

6" RWW FROMCOLLECTION

SYSTEM

PROPOSED CONTROL PANELBY MANUFACTURER

WYE STRAINER BYMANUFACTURER IFREQUIRED

PROPOSEDMANUALSCREEN

NEW MECHANICALSCREEN 02-MS-1111

02-WG-1111

02-WG-1211

6" FM FROMDRAIN RETURNPUMP STATION

12-RWW-PVC

15-RWW-PVC

GRIT BYPASS TOSBR SYTEM

12-INF-PVC

12-INF-PVC

02-SG-113302-SG-112202-SG-1121

02-SG-111202-SG-1111

MANUAL SCREEN INPARALLEL CHANNEL

MODIFICATION SCREEN

SCREEN STRUCTURE

16-RWW-PVC

16-RWW-PVC

02-LE-1111 02-LE-1112

HS HS HS

ON/OFF ON/OFF ON/OFF

2

2

2

A

REVISIONNO.

1DATE

2

B C D

4

3

5

A B C D

E F

J.B.H. / S.A.E.

DRAWN BY

CHECKED BY

DESIGNED BY

G

06/12/2020

DATE

SCALE

H I

1

2

E F G

3

4

H I

5

BAR IS ONE INCH ONORIGINAL DRAWING

IF NOT ONE INCH ONTHIS SHEET. ADJUST

SCALES ACCORDINGLY.

0 1

ACTON MUNICIPAL UTILITY DISTRICTTWDB CWSRF - WWTP NO. 1 IMPROVEMENTS

ENVIRONMENTAL AND CIVIL ENGINEERING402 Cedar Street325-698-5560 PE Firm Registration No. 1151

Abilene, Texas 79601

ENPROTEC/HIBBS & TODD, INC.

PG Firm Registration No. 50103RPLS Firm Registration No. 10011900

16-6633

SHEET No.

SEQUENCE No.

PROJECT NO.:

OF 184

J.L.B.

J.L.B.

06/12/2020

NO SCALE

08Y-210

PROCESS AND INSTRUMENTATIONDIAGRAM

INFLUENT SCREENING

145

2 ADDENDUM NO. 2 07/13/2020

CIM

MA

RO

N T

RA

IL

A

REVISIONNO.

1

DATE

2

B C D

4

3

5

A B C D

E F

DRAWN BY

CHECKED BY

DESIGNED BY

G

07/10/2020

DATE

SCALE

H I

1

2

E F G

3

4

H I

5

BAR IS ONE INCH ONORIGINAL DRAWING

IF NOT ONE INCH ONTHIS SHEET. ADJUST

SCALES ACCORDINGLY.

0 1

ACTON MUNICIPAL UTILITY DISTRICTTWDB CWSRF - WWTP NO. 1 IMPROVEMENTS

ENVIRONMENTAL AND CIVIL ENGINEERING402 Cedar Street325-698-5560 PE Firm Registration No. 1151

Abilene, Texas 79601

PG Firm Registration No. 50103PE Firm Registration No. 1151PG Firm Registration No. 50103

RPLS Firm Registration Nos. 10011900

16-6633SEQUENCE No.

PROJECT NO.:

OF 184SHEET No.

TWDB SUBMITTAL SET1 02/20/2020

CONSTRUCTION SET2 06/12/2020

REVISED INCOMING SERVICE3 07/09/2020

1" = 20'

01E-01ELECTRICAL SITE LAYOUT

30

C D E

BAR IS ONE INCH ONORIGINAL DRAWING

IF NOT ONE INCH ONTHIS SHEET. ADJUST

SCALES ACCORDINGLY.

0 1ENVIRONMENTAL AND CIVIL ENGINEERING402 Cedar Street325-698-5560 PE Firm Registration No. 1151

Abilene, Texas 79601

ENPROTEC/HIBBS & TODD, INC.

PG Firm Registration No. 50103PE Firm Registration No. 1151PG Firm Registration No. 50103

RPLS Firm Registration Nos. 10011900

A

REVISIONNO.

1

DATE

2

B C D

4

3

5

A B C D

E F

DRAWN BY

CHECKED BY

DESIGNED BY

G

07/14/2020

DATE

SCALE

H I

1

2

E F G

3

4

H I

5

BAR IS ONE INCH ONORIGINAL DRAWING

IF NOT ONE INCH ONTHIS SHEET. ADJUST

SCALES ACCORDINGLY.

0 1

ACTON MUNICIPAL UTILITY DISTRICTTWDB CWSRF - WWTP NO. 1 IMPROVEMENTS

ENVIRONMENTAL AND CIVIL ENGINEERING402 Cedar Street325-698-5560 PE Firm Registration No. 1151

Abilene, Texas 79601

ENPROTEC/HIBBS & TODD, INC.

PG Firm Registration No. 50103PE Firm Registration No. 1151PG Firm Registration No. 50103

RPLS Firm Registration Nos. 10011900

16-6633SEQUENCE No.

PROJECT NO.:

OF 184SHEET No.

TWDB SUBMITTAL SET1 02/20/2020

CONSTRUCTION SET2 06/12/2020

REVISED INCOMING SERVICE3 07/09/2020

ADDENDUM NO. 24 07/15/2020

02E-01SCREENING ELECTRICAL PLAN

41

A

REVISIONNO.

1

DATE

2

B C D

4

3

5

A B C D

E F

DRAWN BY

CHECKED BY

DESIGNED BY

G

07/14/2020

DATE

SCALE

H I

1

2

E F G

3

4

H I

5

BAR IS ONE INCH ONORIGINAL DRAWING

IF NOT ONE INCH ONTHIS SHEET. ADJUST

SCALES ACCORDINGLY.

0 1

ACTON MUNICIPAL UTILITY DISTRICTTWDB CWSRF - WWTP NO. 1 IMPROVEMENTS

ENVIRONMENTAL AND CIVIL ENGINEERING402 Cedar Street325-698-5560 PE Firm Registration No. 1151

Abilene, Texas 79601

ENPROTEC/HIBBS & TODD, INC.

PG Firm Registration No. 50103PE Firm Registration No. 1151PG Firm Registration No. 50103

RPLS Firm Registration Nos. 10011900

16-6633SEQUENCE No.

PROJECT NO.:

OF 184SHEET No.

TWDB SUBMITTAL SET1 02/20/2020

CONSTRUCTION SET2 06/12/2020

REVISED INCOMING SERVICE3 07/09/2020

ADDENDUM NO. 24 07/15/2020

1/4" = 1'-0"

04E-01CHLORINE CONTACT BASIN

ELECTRICAL PLAN81

A

REVISIONNO.

1

DATE

2

B C D

4

3

5

A B C D

E F

DRAWN BY

CHECKED BY

DESIGNED BY

G

07/14/2020

DATE

SCALE

H I

1

2

E F G

3

4

H I

5

BAR IS ONE INCH ONORIGINAL DRAWING

IF NOT ONE INCH ONTHIS SHEET. ADJUST

SCALES ACCORDINGLY.

0 1

ACTON MUNICIPAL UTILITY DISTRICTTWDB CWSRF - WWTP NO. 1 IMPROVEMENTS

ENVIRONMENTAL AND CIVIL ENGINEERING402 Cedar Street325-698-5560 PE Firm Registration No. 1151

Abilene, Texas 79601

ENPROTEC/HIBBS & TODD, INC.

PG Firm Registration No. 50103PE Firm Registration No. 1151PG Firm Registration No. 50103

RPLS Firm Registration Nos. 10011900

16-6633SEQUENCE No.

PROJECT NO.:

OF 184SHEET No.

TWDB SUBMITTAL SET1 02/20/2020

CONSTRUCTION SET2 06/12/2020

REVISED INCOMING SERVICE3 07/09/2020

ADDENDUM NO. 24 07/15/2020

NO SCALE

07E-01ELECTRICAL ONE-LINE

DIAGRAM SHEET 1126

A

REVISIONNO.

1

DATE

2

B C D

4

3

5

A B C D

E F

DRAWN BY

CHECKED BY

DESIGNED BY

G

07/10/2020

DATE

SCALE

H I

1

2

E F G

3

4

H I

5

BAR IS ONE INCH ONORIGINAL DRAWING

IF NOT ONE INCH ONTHIS SHEET. ADJUST

SCALES ACCORDINGLY.

0 1

ACTON MUNICIPAL UTILITY DISTRICTTWDB CWSRF - WWTP NO. 1 IMPROVEMENTS

ENVIRONMENTAL AND CIVIL ENGINEERING402 Cedar Street325-698-5560 PE Firm Registration No. 1151

Abilene, Texas 79601

ENPROTEC/HIBBS & TODD, INC.

PG Firm Registration No. 50103PE Firm Registration No. 1151PG Firm Registration No. 50103

RPLS Firm Registration Nos. 10011900

16-6633SEQUENCE No.

PROJECT NO.:

OF 184SHEET No.

TWDB SUBMITTAL SET1 02/20/2020

CONSTRUCTION SET2 06/12/2020

REVISED INCOMING SERVICE3 07/09/2020

NO SCALE

07E-03ELECTRICAL ONE-LINE

DIAGRAM SHEET 3128

A

REVISIONNO.

1

DATE

2

B C D

4

3

5

A B C D

E F

DRAWN BY

CHECKED BY

DESIGNED BY

G

07/14/2020

DATE

SCALE

H I

1

2

E F G

3

4

H I

5

BAR IS ONE INCH ONORIGINAL DRAWING

IF NOT ONE INCH ONTHIS SHEET. ADJUST

SCALES ACCORDINGLY.

0 1

ACTON MUNICIPAL UTILITY DISTRICTTWDB CWSRF - WWTP NO. 1 IMPROVEMENTS

ENVIRONMENTAL AND CIVIL ENGINEERING402 Cedar Street325-698-5560 PE Firm Registration No. 1151

Abilene, Texas 79601

ENPROTEC/HIBBS & TODD, INC.

PG Firm Registration No. 50103PE Firm Registration No. 1151PG Firm Registration No. 50103

RPLS Firm Registration Nos. 10011900

16-6633SEQUENCE No.

PROJECT NO.:

OF 184SHEET No.

TWDB SUBMITTAL SET1 02/20/2020

CONSTRUCTION SET2 06/12/2020

REVISED INCOMING SERVICE3 07/09/2020

ADDENDUM NO. 24 07/15/2020

NO SCALE

07E-04ELECTRICAL ONE-LINE

DIAGRAM SHEET 4129

A

REVISIONNO.

1

DATE

2

B C D

4

3

5

A B C D

E F

DRAWN BY

CHECKED BY

DESIGNED BY

G

07/14/2020

DATE

SCALE

H I

1

2

E F G

3

4

H I

5

BAR IS ONE INCH ONORIGINAL DRAWING

IF NOT ONE INCH ONTHIS SHEET. ADJUST

SCALES ACCORDINGLY.

0 1

ACTON MUNICIPAL UTILITY DISTRICTTWDB CWSRF - WWTP NO. 1 IMPROVEMENTS

ENVIRONMENTAL AND CIVIL ENGINEERING402 Cedar Street325-698-5560 PE Firm Registration No. 1151

Abilene, Texas 79601

ENPROTEC/HIBBS & TODD, INC.

PG Firm Registration No. 50103PE Firm Registration No. 1151PG Firm Registration No. 50103

RPLS Firm Registration Nos. 10011900

16-6633SEQUENCE No.

PROJECT NO.:

OF 184SHEET No.

TWDB SUBMITTAL SET1 02/20/2020

CONSTRUCTION SET2 06/12/2020

REVISED INCOMING SERVICE3 07/09/2020

ADDENDUM NO. 24 07/15/2020

NO SCALE

07E-09INSTRUMENTATION ONE-LINE

DIAGRAM SHEET 2134

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ACTON MUNICIPAL UTILITY DISTRICTTWDB CWSRF - WWTP NO. 1 IMPROVEMENTS

ENVIRONMENTAL AND CIVIL ENGINEERING402 Cedar Street325-698-5560 PE Firm Registration No. 1151

Abilene, Texas 79601

ENPROTEC/HIBBS & TODD, INC.

PG Firm Registration No. 50103PE Firm Registration No. 1151PG Firm Registration No. 50103

RPLS Firm Registration Nos. 10011900

16-6633SEQUENCE No.

PROJECT NO.:

OF 184SHEET No.

TWDB SUBMITTAL SET1 02/20/2020

CONSTRUCTION SET2 06/12/2020

REVISED INCOMING SERVICE3 07/09/2020

ADDENDUM NO. 24 07/15/2020

NO SCALE

07E-16ELECTRICAL DUCTBANK

SECTIONS141

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BAR IS ONE INCH ONORIGINAL DRAWING

IF NOT ONE INCH ONTHIS SHEET. ADJUST

SCALES ACCORDINGLY.

0 1

ACTON MUNICIPAL UTILITY DISTRICTTWDB CWSRF - WWTP NO. 1 IMPROVEMENTS

ENVIRONMENTAL AND CIVIL ENGINEERING402 Cedar Street325-698-5560 PE Firm Registration No. 1151

Abilene, Texas 79601

ENPROTEC/HIBBS & TODD, INC.

PG Firm Registration No. 50103PE Firm Registration No. 1151PG Firm Registration No. 50103

RPLS Firm Registration Nos. 10011900

16-6633SEQUENCE No.

PROJECT NO.:

OF 184SHEET No.

TWDB SUBMITTAL SET1 02/20/2020

CONSTRUCTION SET2 06/12/2020

REVISED INCOMING SERVICE3 07/09/2020

ADDENDUM NO. 24 07/15/2020

NO SCALE

07E-17ELECTRICAL CONDUIT

SCHEDULE SHEET 1142

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DRAWN BY

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G

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BAR IS ONE INCH ONORIGINAL DRAWING

IF NOT ONE INCH ONTHIS SHEET. ADJUST

SCALES ACCORDINGLY.

0 1

ACTON MUNICIPAL UTILITY DISTRICTTWDB CWSRF - WWTP NO. 1 IMPROVEMENTS

ENVIRONMENTAL AND CIVIL ENGINEERING402 Cedar Street325-698-5560 PE Firm Registration No. 1151

Abilene, Texas 79601

ENPROTEC/HIBBS & TODD, INC.

PG Firm Registration No. 50103PE Firm Registration No. 1151PG Firm Registration No. 50103

RPLS Firm Registration Nos. 10011900

16-6633SEQUENCE No.

PROJECT NO.:

OF 184SHEET No.

TWDB SUBMITTAL SET1 02/20/2020

CONSTRUCTION SET2 06/12/2020

REVISED INCOMING SERVICE3 07/09/2020

ADDENDUM NO. 24 07/15/2020

NO SCALE

07E-18ELECTRICAL CONDUIT

SCHEDULE SHEET 2143

ADDENDUM NO. 2

Acton Municipal Utility District TWDB WWTP No. 1 Improvements Mechanical Coarse Screen Project No. 6633 11075-1 July 15, 2020

SECTION 11075

MECHANICAL COARSE SCREEN PART 1 GENERAL

1.1 SUMMARY

A. Section Includes:

1. New mechanical screen rated for 2.79 MGD.

2. Fully automatic, self-cleaning perforated plate basket type influent

screen for removing floating, particulate, and fibrous material from municipal wastewater and for conveying, washing, dewatering, compacting, and bagging the screenings.

3. Screen supports, safety devices, controls, local control panel, and all other accessories required for a complete and operable system.

4. Manufacturer representation and assistance during installation, startup, and testing.

1.2 RELATED SECTIONS: A. Section 11005 “Equipment Basic Requirements” (including motor

specifications).

B. Section 16950 “Vendor Supplied Control Panels”.

1.3 REFERENCES A. References: Following is a list of standards, which might be referenced in

this Section: 1. American Iron and Steel Institute (AISI).

2. National Electrical Manufacturer’s Association (NEMA): MG-1,

Motors and Generators.

3. American Gear Manufacturers Association (AGMA).

4. American National Standards Institute (ANSI).

5. American Welding Society (AWS).

1.4 SYSTEM DESCRIPTION A. Install, startup, and test new automatic, self-cleaning screen. The screen

shall be installed in a new concrete channel as shown on Drawings. The screen shall be automatic and accomplish screening by means of a perforated plate basket.

ADDENDUM NO. 2

Acton Municipal Utility District TWDB WWTP No. 1 Improvements Mechanical Coarse Screen Project No. 6633 11075-2 July 15, 2020

B. The equipment shall be of manufacturer’s latest design and shall be fabricated of materials and in a fashion, which will fully perform the functions described below.

C. The manufacturer shall be responsible for coordinating the screen components so that screened material is delivered to the container without spillage or water leakage.

D. Manufacturer shall be responsible for the adequacy and compatibility of the equipment and controls.

1.5 SUBMITTALS A. The following submittals are required, at a minimum:

1. Product Data shall include the following:

a. Descriptive literature, brochures, catalogs, cut-sheets and

other detailed descriptive material of the equipment.

b. Motor characteristics and performance information.

c. Gear reducer data including service factor, efficiency, torque rating, and materials.

d. Parts list including a list of recommended spare parts.

e. Equipment weights and lifting points.

f. Design parameters for the screen, including flow rates and head losses for clean and partially blinded conditions.

g. Wash water usage information including maximum gallons per day required.

h. Calculation of perforation flow through velocity based on peak flow.

2. Shop Drawings shall include the following: a. Manufacturer’s installation drawings including dimensions,

clearances required, location and size of each connection, and proposed width of modified channel.

b. Layout, sizes, types and materials for anchor bolts to be furnished.

c. Complete wiring diagrams for power, timers, signal and control, and data on controls to be furnished, including terminals and numbers.

3. Information Submittals:

ADDENDUM NO. 2

Acton Municipal Utility District TWDB WWTP No. 1 Improvements Mechanical Coarse Screen Project No. 6633 11075-3 July 15, 2020

a. Special shipping, storage and protection, and handling instructions.

b. Manufacturer’s instructions for installation.

c. Manufacturer’s Certificate of Proper Installation.

d. Manufacturer and manufacturer’s representative qualifications.

e. Location of nearest stocking distributor of spare parts.

f. Welding certificates.

4. Operation and maintenance manual covering all equipment and controls.

5. All deviations from contract documents shall be clearly identified and approved in writing by the ENGINEER.

6. Any other information necessary for the ENGINEER to determine compliance with the specifications.

7. Partial or incomplete submittals will not be reviewed by ENGINEER.

1.6 QUALITY ASSURANCE A. All equipment of each type specified in this section shall be supplied by a

single manufacturer.

B. Manufacturer shall maintain a complete stock of spare parts commonly needed for the equipment specified at a location within the State of Texas, or shall furnish spare parts within forty-eight (48) hours of request.

C. Manufacturer Qualifications: Manufacturer shall be regularly engaged in the manufacturing and production of the type of screen proposed for a minimum of five (5) years. The manufacturer must have a minimum of ten (10) installations in the United States of the type of screen proposed, each in satisfactory service. Any manufacturer that does not meet these qualifications must provide a five (5) year full parts and service warranty. All manufacturers must provide a reference list with contact names and phone numbers to verify installations.

D. Manufacturer's installation report is required prior to final acceptance.

E. Excessive vibration of equipment while operating shall be cause for rejection.

F. Each screen shall be factory assembled and shipped to the site as a complete unit.

G. Stainless steel construction:

ADDENDUM NO. 2

Acton Municipal Utility District TWDB WWTP No. 1 Improvements Mechanical Coarse Screen Project No. 6633 11075-4 July 15, 2020

1. All structural stainless steel components shall conform to the requirements of “Specifications for the Design, Fabrication and Erection of Structural Steel for Buildings” published by the American Institute of Steel Construction.

2. The equipment manufacturer’s shop welds, welding procedures, welders and welding operators shall be qualified and certified in accordance with the requirements of the latest edition of ANSI/AWS D1.1 “Structural Welding Code – Steel” published by the American Welding Society.

3. Fabricate all parts and assemblies from sheets and plates of 316 stainless steel with a 2D finish conforming to AISI 316 and ASTM A666, unless noted otherwise. Fabricate all rolled or extruded shapes to conform to ASTM A276. Fabricate all tubular products and fittings to conform to ASTM A269, A351 and A403.

4. Do all welding in the factory using shielded arc, inert gas, MIG or TIG method. Add filler wire to all welds to provide for a cross section and weld metal equal to or greater than the parent metal. Fully penetrate butt welds to the interior surface and provide gas shielding to interior and exterior of the joint.

5. Field welding of stainless steel will not be permitted.

6. The equipment, after its fabrication, shall undergo passivation (pickling) by immersion to ensure maximum resistance to corrosion. All stainless steel components and structures shall be submersed in a chemical bath of nitric acid and hydrofluoric acid to remove any residues that may be present on the material as a result of forming, manufacture, or handling. After removal from the pickling bath, the equipment shall be washed with a high-pressure wash of cold water to remove any remaining surface debris and promote the formation of an oxidized passive layer which is critical to the long life of the stainless steel.

H. If the equipment being offered differs from these specifications, all revisions in the design and construction of the structure, piping, appurtenant equipment, electrical work, etc. required to accommodate such a substitution shall be made at no additional cost to the OWNER.

1.7 DELIVERY, STORAGE AND HANDLING A. All equipment shall be shipped and delivered fully assembled, except where

partial disassembly is required in order to conform to transportation regulations or for the protection of components.

B. Delivery, storage, and handling shall be in full accordance with manufacturer's instructions. Motors, Controls and other electrical components shall be stored in a weatherproof enclosure.

ADDENDUM NO. 2

Acton Municipal Utility District TWDB WWTP No. 1 Improvements Mechanical Coarse Screen Project No. 6633 11075-5 July 15, 2020

1.8 WARRANTY A. The manufacturer shall provide a warranty on equipment against

manufacturer’s defects for twelve (12) months, commencing on the date of Owner-accepted substantial completion of the project. If the equipment should fail during the warranty period due to a defective part, it shall be replaced and the unit restored at no cost to the owner, including both service and parts.

PART 2 PRODUCTS

2.1 ACCEPTABLE MANUFACTURERS A. Subject to compliance with the Contract Documents, the following

manufacturers are acceptable (in alphabetical order): 1. Enviro-Care. 2. Huber. 3. JWC. 4. Lakeside. 5. Spirac. 6. WTP Equipment Corp. 7. Engineer approved equal.

2.2 SYSTEM DESCRIPTION

A. General Requirements

1. The screen mechanism shall be capable of screening raw wastewater

and discharging the screenings into a screenings container (by others as shown).

2. The screen shall provide positive screening up to at least the peak flow listed below.

3. The screening equipment shall produce dewatered screenings capable of passing the EPA Paint Filter Test as described in method 9095 of EPA Publication SW 486.

4. All equipment shall be designed for and capable of both continuous and intermittent operation. The complete mechanical screen device including screen frame, plate and all moving parts, shall be able to withstand the loading from a 36 inch water differential from upstream to downstream.

5. The structural integrity of the screening equipment shall be maintained at peak flow without causing the channel to overflow or the screening equipment to fail or cease operation.

6. All equipment provided including electrical panels, instrumentation, and controls shall be specifically designed for wastewater treatment service and the environment encountered in this installation, including corrosion resistance. The environment will be moist and

ADDENDUM NO. 2

Acton Municipal Utility District TWDB WWTP No. 1 Improvements Mechanical Coarse Screen Project No. 6633 11075-6 July 15, 2020

corrosive, containing hydrogen sulfide and other corrosive gases encountered in municipal wastewater treatment plants.

7. All equipment, supports, anchors and fasteners shall be of adequate strength to withstand loads associated with starting, turbulence, thrusts from liquid movement, thermal expansion and contraction and other loads encountered under normal operating conditions.

8. The equipment, sizes, materials, and arrangements described in this specification section shall be considered minimum limits of acceptability. The equipment manufacturer shall be responsible for design, arrangement, and performance of all equipment supplied under this section. Arrangements other than those shown on plans shall be subject to Engineer’s approval.

2.3 PERFORMANCE AND DESIGN REQUIREMENTS A. Number of screens: One (1) new.

B. Tag Number: 02-MS-01.

C. Location: Outdoors in proposed 2-ft by 6-ft (max upstream SWD = 3-ft)

screen channel. See Drawings.

D. Ambient temperature range: 0°F to 110°F.

E. Dimensions of Screen: 1. For channel dimensions, see Drawings. 2. For discharge height, see Drawings. 3. Minimum Screen basket diameter: 16”. 4. Screen incline: 35° to 45°. 5. Screen opening size: 1/4-inch (6 mm).

F. Design Capacity per Screen:

1. Average design flow through each screen unit: 0.93 MGD.

2. Peak design flow through each screen unit: 2.79 MGD.

3. Maximum upstream water level: 36” with 75% screen blockage,

given a downstream water depth of 12”.

4. Downstream water surface elevation: 12-18” at peak design flow (controlled by adjustable weir gates and slide gates).

5. The average clear perforation flow-through velocity shall not exceed 3.0 ft/sec at the peak clean water flow specified above.

G. The screen shall be capable of processing spherical objects with a diameter of 3-1/8”. Such objects shall be conveyed through the auger and shall be discharged with the screenings.

ADDENDUM NO. 2

Acton Municipal Utility District TWDB WWTP No. 1 Improvements Mechanical Coarse Screen Project No. 6633 11075-7 July 15, 2020

H. Screw (auger): 1. Either a shafted or shaftless design is acceptable. 2. Wet screenings capacity of auger: 21 cubic feet per hour. 3. Minimum tube outside diameter: 8.6 inches. 4. Minimum shaft diameter (if provided): 3.4 inches. 5. Approx. rotational speed: 9 rpm.

I. Screen shall be suitable for the available wash water supply:

1. Effluent water. Manufacturer shall provide any required strainers. 2. Available pressure: 70 psi. 3. Maximum usage: 16 gallons per minute (gpm); up to 5,000 gallons

per day. 4. Supply connection size: 1.25 inch. Contractor shall adapt the supply

to the connection size provided on the screen.

J. Power Supply: 480 V, 60 Hz, 3 phase.

2.4 MATERIALS A. Unless otherwise noted in these specifications, all components of the screen

equipment and accessories shall be Type 316 stainless steel.

B. Brush shall be stainless steel backed Nylon or have nylon bristles molded into a plastic core.

C. Seals between the screen and the channel wall shall be neoprene.

D. Minimum material thicknesses: 1. Upper basket flange thickness, inch 10/64 2. Perforated plate for screen basket thickness, inch 1/8 3. Screen body thickness, inch 1/8 4. Auger tube thickness, inch 0.1 5. Screw flights thickness (minimum), inch 0.2 6. Screw flight in compaction zone thickness, inch 25/64 7. Shaft tube thickness (if provided), inch 0.2 8. Flange for support of the gearbox thickness, inch 0.47 9. Bagging device 12 gauge

2.5 SCREEN EQUIPMENT

A. General:

1. The screen shall have a semi-cylindrical screen basket made of

perforated plate and an integral screw conveyor and screenings press. The screw in the basket shall be provided with a brush on its flight for screen cleaning. The screen shall use a single drive for screening, conveying, dewatering and compressing the screened material.

ADDENDUM NO. 2

Acton Municipal Utility District TWDB WWTP No. 1 Improvements Mechanical Coarse Screen Project No. 6633 11075-8 July 15, 2020

2. The screen basket shall be attached to the screen body with bolts and nuts, permitting easy removal of the screen basket.

3. The screen shall be fitted to and sealed in the existing channel to prevent wastewater from bypassing the screen.

4. The screen shall be provided with an upper support flange and a conical transition piece between the screen basket and auger tube. The flange shall be machined after welding to ensure proper alignment of the screen basket and auger.

5. The screen shall be provided with a pivoting support stand allowing for easy removal of the screen basket from the channel for maintenance purposes.

2.6 SCREENINGS CONVEYOR AND WASH-PRESS A. The screen shall be cleaned with a stainless steel screw conveyor with

helicoid-shaped flights. The screw shall move screenings up through a compaction zone and discharge them into bags. Discharge chute shall allow debris to be transferred from discharge point into the debris container (provided by Owner).

B. To minimize odors and nuisance, the conveyance, dewatering and compaction zones shall be completely enclosed.

C. The flights of the screw in the basket shall be provided with a ¼ inch thick hardened stainless steel strip having the same width as the flights of the screw. The strip shall be welded to the face of the flight, on both sides, over the full length of the screen basket. The flights of the screw shall be machined to match the screen basket such that the face of the strip is parallel to the screen basket’s inner surface.

D. For Shaftless Spiral Screens: The spiral screw shall be shaftless with the exception of the compaction and discharge areas. The screw shall be fabricated from type 316 stainless steel. The inner flight shall have a minimum thickness of .39 inch, and the outer flight shall have a minimum thickness of .59 inch. Additional flight length of type 316 stainless steel is welded to the spiral to increase the screw OD in the basket and transition areas while maintaining a constant ID. The screw shall pass through the conic section of the frame expanding from 7.68 inch OD in the conveyor tube to 17.13 inch OD at the screening basket. To aid in the prevention of roll back in the basket area, the screw flight shall have a minimum height of 7.28 inch. Refer to section 2.4 A for materials.

E. A brush shall be attached to the screw flight over the entire length of the screen basket. The brush shall be attached by means of stainless steel clips or fasteners.

F. Two (2) to four (4) anti-rotation bars or wear bars shall be welded to the inside of the transport tube along its longitudinal axis. For shafted spirals, the screenings screw conveyor shall not be in contact with the anti-rotation bars

ADDENDUM NO. 2

Acton Municipal Utility District TWDB WWTP No. 1 Improvements Mechanical Coarse Screen Project No. 6633 11075-9 July 15, 2020

during normal operation. For shaftless spirals, the wear bars shall be replaceable without requiring welding or replacement of the conveyor tube.

G. A flange shall be welded to the conical transition piece to support and allow for removal of the screen basket. A gear box support flange shall be welded to the upper end of the auger tube for support and removal of the drive assembly.

H. A stainless steel screw with helical flight shall be installed in the auger tube for conveying and compaction of the screened material.

I. After all flanges are welded to the auger tube, the faces of the flanges shall be machined on a lathe such that they are exactly perpendicular to the tube axis.

J. A compaction zone shall be provided as an integral part of the screw conveyor and tube. The compaction zone shall be designed to form a plug of screenings material and to return water released from the screened material through perforations machined into the screenings transport tube.

K. An alternate compaction zone can be provided where the compaction zone shall be a two chambered rectangular section at the end of the transport tube to dewater the screened material. 1. The first chamber of the compaction zone shall be a cylindrical drum

encased by the rectangular enclosure. The drum shall be constructed from .12 inch thick type 316 stainless steel. The drum shall maintain the same ID as the conveyor tube, and shall have perforations on its underside to allow water to drain from the pressed screenings. The enclosure shall be constructed from type 316 stainless steel and shall be supplied with a pipe stub to provide drainage of the compaction zone. A length of flexible hose shall be provided to direct the pressate back into the channel downstream of the screen.

2. The second chamber of the enclosure shall be an open rectangular discharge section. The cross sectional expansion of this area from the cylindrical compaction drum allows the dewatered material to freely fall away from the spiral shaft. Designs that require reversed flights or cutters to effectively discharge material from the unit are not acceptable.

3. A top mounted, hinged access door is provided to the compaction zone and discharge section for maintenance. The door shall expose the entire length and width of the compaction and discharge areas in order to provide complete unobstructed access to these areas. The door shall be constructed from type 316 stainless steel and shall be mounted with stainless steel hinges. A safety microswitch shall be installed to prevent the screen from running while accessing the compaction zone and discharge section. Designs incorporating access from underneath the compaction zone or the vertical discharge section are non hygienic and shall not be acceptable.

ADDENDUM NO. 2

Acton Municipal Utility District TWDB WWTP No. 1 Improvements Mechanical Coarse Screen Project No. 6633 11075-10 July 15, 2020

L. The compaction zone housing shall be split glass fiber reinforced plastic or Type 316 stainless steel. The housing shall be furnished with gaskets and bolts, and shall be easily removable for access. Designs requiring removal of the drive assembly, discharge head, or screw conveyor to gain access to the compaction zone will not be acceptable. The housing shall be provided with a drain connection at its lowest point and a clamped flexible PVC hose for drain water whose other end shall discharge to the influent channel. The housing shall also be provided with a flush connection to allow periodic cleaning of the compaction zone.

M. The upper end of the auger tube shall be provided with a discharge chute for the screenings. The chute shall have a slope of at least 40 degrees.

N. The auger tube shall be provided with lifting lugs to facilitate installation and removal of the entire screen.

O. Manufacturer shall provide all necessary supports and braces for the screen.

2.7 SCREEN AND SCREENINGS WASH SYSTEM A. An automatic screenings wash system shall be provided and shall be suitable

for wash water parameters above.

B. The screenings wash zone of the conveyor tube shall be provided with a minimum of two nozzles at its circumference. A spray bar shall be provided above the screw in the screen basket. The compaction zone housing shall be provided with a ring flush system to ensure complete flushing of the compaction zone housing. All water access points shall be provided with solenoid valves and piping and/or flexible reinforced PVC hoses.

C. The common water connection shall be provided with a brass body Y-strainer (by manufacturer). The strainer shall include a removable and washable stainless steel 20-mesh (800 micron) filter element. A water manifold with one input and a minimum of two output water connections shall be provided. The water input connection shall have a minimum diameter of 1”.

D. The wash system shall be operated on an intermittent basis only. Wash systems which operate continuously will not be acceptable.

E. The solenoid valves shall be operated by the programmable logical controller or a programmable control relay. Individual manual operation of each solenoid shall also be possible from the control panel.

F. Solenoid valves shall be brass body, 2-way, and designed for 120 VAC operation with an explosion-proof rating. Solenoid valves shall be normally closed and rated for up to 100 psig.

2.8 GEAR MOTOR DRIVE A. The screw shall be driven by a shaft mounted geared motor. The geared

motor shall have a minimum service factor of 1.0 equivalent to an AGMA Class I rating.

ADDENDUM NO. 2

Acton Municipal Utility District TWDB WWTP No. 1 Improvements Mechanical Coarse Screen Project No. 6633 11075-11 July 15, 2020

B. The gear reducer shall be bolted to a machined flange welded to the upper end of the auger tube.

C. The gear reducer shall be driven by a minimum 1.0 hp to a maximum 2.0 hp, 1800 rpm, 480 volt, 3-phase, 60 Hertz, Class I, Division 1, continuous-duty motor with leads to a conduit box for outdoor operation.

2.9 BAGGER A. The discharge chute shall be furnished with a stainless steel bagging device

to contain and encase dewatered screenings. The bagging device shall use endless bags.

B. The screenings bagger shall be designed to be fitted with replaceable plastic bags.

2.10 ANCHORAGE AND FASTENERS A. Equipment manufacturer shall determine sizes and furnish anchor bolts of

sufficient size and strength to securely anchor each item of equipment. All non-embedded anchors shall be capsule or epoxy Type 316 stainless steel. Expansion type anchors are not acceptable. The CONTRACTOR shall set the bolts in accordance with manufacturer recommendations.

B. All equipment hardware and fasteners including nuts, bolts, and washers shall be Type 316 stainless steel.

2.11 OUTDOOR WEATHER PROTECTION A. The screenings transport tube shall be furnished with heat tracing and

thermal insulation which shall enclose the screenings transport tube, compaction and dewatering zone, and all spray wash piping. Exposed wash water solenoid valves and shall be heat traced and installed in a 316 stainless steel box attached to the screen by the manufacturer. All hoses on the screen shall also be heat taped and insulated by the manufacturer. All other exposed, exterior wash water supply piping coming to the screen shall be heat traced and insulated in the field by the contractor per Section 15183.

B. The outdoor weather protection system shall include self-regulating heat tracing, adjustable thermostat, insulation and a stainless steel protective jacket. Heat tracing supplied by the manufacturer shall be powered from the manufacturer’s control panel.

C. The heat tracing system shall be suitable for operation in a Class 1 Division 2 hazardous environment, at a minimum temperature of -13 deg F (-25 deg C), and shall be powered from the main control panel.

D. Where the wash water supply and electrical wiring conduit penetrate the stainless steel cover bulkhead adapters shall be provided.

E. All components requiring service or maintenance shall be easily accessible.

ADDENDUM NO. 2

Acton Municipal Utility District TWDB WWTP No. 1 Improvements Mechanical Coarse Screen Project No. 6633 11075-12 July 15, 2020

2.12 SPARE PARTS A. As a minimum, the following Spare Parts shall be included and supplied

together with the equipment: 1. 2 cleaning brushes. 2. 1 Solenoid valve rebuild kit. 3. Boxes of endless bags totaling at least 1400 ft.

2.13 INSTRUMENTATION AND CONTROLS

A. Manufacturer shall provide a local control panel and all instrumentation and

controls necessary for the fully automatic operation of the screen.

B. The control system shall allow cleaning parameters of the screen to be changed via the local control panel display. Systems which do not offer this feature shall not be acceptable for this project.

C. Provide capability to operate screen on liquid level control signal, timed, or continuous basis. A preset high upstream liquid level (indicative of blinding of the screen) and high downstream liquid level (indicative of a closed downstream gate) shall initiate operation of the screen drive, in connection with a timer. Screens which operate continuously or via timer only will not be acceptable.

D. Control panel shall be NEMA 4X 316 stainless steel suitable for outdoor installation on unistrut frame provided by Contractor. Panel shall include the following: 1. Front cover. 2. Full window. 3. Lockable door latch. 4. Door-interlocked and fused disconnect. 5. 600 VAC terminal block. 6. NEMA reversing motor starter and MCP type circuit breaker for

screen motor. 7. Panel heater with thermostat. 8. Control power transformer with 120 VAC transient voltage surge

compressor (TVSC) and fused primary and secondary. 9. Programmable logic controller (PLC), Allen Bradley Micrologix 1400.

(IN LIEU OF THE PLC A PROGRAMMABLE CONTROL RELAY MAY BE USED TO PROVIDE NECESSARY CONTROL LOGIC AND MONITOR EQUIPMENT MOUNTED ELECTRICAL DEVICES

10. Operator Interface (OIU), Allen Bradley PanelView C400. 800 SERIES WITH A 4-INCH SCREEN. (NOT REQUIRED WITH THE PROGRAMMABLE RELAY)

11. Hand-Off-Auto selector switches for the following: a. Screen drive. b. Screen forward-off-reverse. c. Screenings washing system. d. Screen press zone flushing. e. Pilot lights for:

ADDENDUM NO. 2

Acton Municipal Utility District TWDB WWTP No. 1 Improvements Mechanical Coarse Screen Project No. 6633 11075-13 July 15, 2020

i Control power on (white). ii Screen running (green). iii Screen high level (amber). iv Screen fault (red).

f. E-stop push button (red). g. Screen reset push button (black). h. Door mounted elapsed time meters for the following:

i Screen drive.

i. Digital inputs for the following:

i Upstream water level. ii Downstream water level. iii One spare input.

j. Remote dry contact outputs for the following:

i Screen running. ii General alarm. iii One spare output.

k. Flashing alarm light and alarm horn with silencer-reset button. l. Plastic Nameplates.

2.14 INSTRUMENTATION

A. Level sensor/transmitters and/or controllers: Manufacturer shall supply two

ultrasonic level sensors, located upstream and downstream of the screen. Provide stainless steel mounting hardware and expansion anchors. Any enclosures shall be rated NEMA 4X.

B. Safety Microswitch: A 120V safety switch shall be factory mounted to the compaction and discharge zone access door. The microswitch shall prevent the unit from operating while the door is open. The switch housing shall be rated NEMA 4X.

C. Thermostat: One (1) ambient temperature thermostat shall be provided to control power to the heat trace cable. The thermostat shall be 120 Volt, single phase, 60 Hz with a NEMA 4X housing. The temperature setpoint shall be selectable by an adjustable dial.

PART 3 EXECUTION

3.1 FIELD PREPARATION AND PAINTING A. Contractor shall touch-up all shipping damage to the paint as soon as the

equipment arrives on the job site.

B. Contractor shall supply paint for field touch-up and field painting.

ADDENDUM NO. 2

Acton Municipal Utility District TWDB WWTP No. 1 Improvements Mechanical Coarse Screen Project No. 6633 11075-14 July 15, 2020

C. Contractor shall finish paint electrical motors, speed reducers, and other self-contained or enclosed components with oil-resistance enamel.

D. Contractor shall coat all stainless steel bolts and nut threads with a non-seizing compound prior to final assembly.

3.2 INSTALLATION, START-UP AND OPERATOR TRAINING A. Contractor shall verify all dimensions in the field to ensure compliance of

equipment dimensions with the drawings. Contractor shall notify Engineer of any significant deviations.

B. Installation of the equipment shall be in strict accordance with the contract documents and the manufacturer’s written instructions.

C. Manufacturer shall furnish the services of a factory-trained Service Representative for one (1) trip including one (1) eight-hour day on-site to inspect the installation, observe start up, and provide operator training. 1. Equipment shall not be energized, or “bumped” to check the

electrical connection for motor rotation without the Service Representative present.

2. The Service Representative shall make all necessary adjustments and settings to the controls. In particular, Service Representative shall verify the level setpoints for the screen.

3. The Service Representative shall demonstrate proper operation of screen. The screen shall operate automatically based on the water level.

END OF SECTION

ADDENDUM NO. 2

Acton Municipal Utility District TWDB WWTP No. 1 Improvements FRP Pipe Project No. 6633 15068-1 July 15, 2020

SECTION 15068

FIBERGLASS REINFORCED PIPE

PART 1 GENERAL

1.1 WORK: A. The WORK of this Section includes providing fiberglass reinforced piping

systems with fiberglass reinforced fittings, complete.

1.2 RELATED SECTIONS: A. The work of the following sections applies to the work of this section. Other

sections of the specifications, not referenced below, shall also apply to the extent required for proper performance of this work. 1. SECTION 15060 – PIPES AND PIPE FITTINGS

1.3 SPECIFICATIONS AND STANDARDS:

A. Except as otherwise indicated, the current editions of the following apply to

the WORK of this Section: 1. ASTM D 2310 Classification for Machine-Made Reinforced

Thermosetting Resin Pipe.

2. ASTM D 2992 Method for Obtaining Hydrostatic Design Basis for Reinforced Thermosetting Resin Pipe and Fittings.

3. ASTM D 2996 Specification for Filament-Wound Reinforced Thermosetting Resin Pipe.

1.4 SHOP DRAWINGS AND SAMPLES: A. The following shall be submitted in compliance with Section 01300:

1. Detailed information on pipe manufacturing process, including resin,

filament winding, and dimensions.

2. Information on joint adhesive.

3. Information and dimensions of pipe fittings.

1.5 SERVICES OF MANUFACTURER: A. Inspection, Startup, and Field Adjustment: An authorized representative of the

manufacturer shall visit the site to instruct the CONTRACTOR'S employees on handling, installing, and supporting the pipe and assembling joints.

ADDENDUM NO. 2

Acton Municipal Utility District TWDB WWTP No. 1 Improvements FRP Pipe Project No. 6633 15068-2 July 15, 2020

PART 2 PRODUCTS

2.1 GENERAL:

A. Manufacturing Method: Fiberglass reinforced pipe (FRP) shall be machine-made, reinforced, thermosetting resin, pressure pipe, manufactured by the filament winding process, conforming to ASTM D 2996 or ASTM D 2310, suitable for exposed or buried service. The pipe shall be made of epoxy resin or vinylester, best suited for the individual application, with continuous glass filaments wound over a resin-rich reinforced liner, with fittings made of the same material.

B. Design Criteria: 1. Size range (inches) - 1 through 16. 2. Min. liner thickness (in) - 0.020. 3. Laying length (ft) - 18 to 30. 4. Temperature rating (degrees F) - 200 max. 5. Working pressure rating at 200 degrees F - 150 min. according

to ASTM D2992 (psi)

C. Joints: The pipes shall have bell by spigot ends for quick-set adhesive bonded joints, or flanged ends drilled to match ANSI B16.5 drillings. All flanged joints shall have Type 316 stainless steel bolts and nuts.

D. Fittings: All pipe fittings shall be of fiberglass reinforced, strong, filament-wound construction suitable for adhesive bonded or flanged joints.

2.2 MANUFACTURERS: A. Products of the type indicated shall be manufactured by one of the following:

1. Bondstrand (Harrington Industrial Plastics, Inc.). 2. Smith Fiberglass (Ryan Herco Industrial Plastics). 3. Or Engineer approved equal.

PART 3 EXECUTION

3.1 INSTALLATION:

A. General: Fiberglass reinforced plastic pipes and fittings shall be installed in

accordance with the manufacturer's written instructions.

B. Expansion: Sufficient allowance must be made for expansion and contraction, due to the high coefficient of thermal expansion of fiberglass reinforced pipe.

C. Supports: Care shall be taken to provide sufficient pipe supports, anchors, and guides to eliminate excessive stress on the piping. Supports shall be installed on each side of valves, strainers, and any other heavy equipment in the pipeline.

D. Adhesive: Pipe ends must be shaved clean before applying epoxy adhesive for joints. All adhesive must be fresh to ensure joint integrity.

ADDENDUM NO. 2

Acton Municipal Utility District TWDB WWTP No. 1 Improvements FRP Pipe Project No. 6633 15068-3 July 15, 2020

E. Tracer: All buried fiberglass pipes shall be installed with metallic tracer tape attached to the pipe, to facilitate locating the pipe.

F. Any exposed glass fibers due to cutting or drilling of the pipe must be covered with a coat of epoxy. Pipes or fittings with damaged surfaces or exposed glass fibers shall be rejected and replaced.

3.2 FIELD TESTING: A. Unless otherwise indicated, all fiberglass reinforced pipes shall be field tested

after installation and before concealment or burying, with a hydraulic test to 150 percent of the maximum working pressure for a period of 4 hours. Any apparent leaks must be corrected and the pipe retested until no further leaks appear.

END OF SECTION

ADDENDUM NO. 2

Acton Municipal Utility District TWDB WWTP No. 1 Improvements Diesel Generator and Controls Project No. 6633 16210-1 July 15, 2020

SECTION 16210

DIESEL ENGINE GENERATOR AND CONTROLS PART 1 GENERAL

1.1 SECTION INCLUDES

A. This section specifies the furnishing and installation of a packaged electric

generating plant.

B. The packaged, diesel engine-electric generating plant shall be pre-wired, pre-piped, assembled, and aligned on a single skid type base. The packaged system of new, unused equipment of the manufacturer's latest design includes all necessary instruments, devices, switches, and other appurtenances for proper operation of the unit: supplies steel safety guards around all external rotating parts, and provides a unit on which adjustments, repairs, and normal maintenance are possible without the use of special tools. The supplier will be responsible for the proper performance of the complete unit and support systems. The supplier must have complete parts and service available on a 24-hour basis in the area of the job site. Stock for replacement parts of the engine/generator must be maintained by the supplier.

C. All equipment provided shall be manufactured by a single source of supply, and supplied by a manufacturer who has been continuously engaged in the manufacture of industrial grade Power System products for a minimum of 25 years. The manufacturer shall have test facilities available to test the proposed equipment and demonstrate the equipment will meet the project specifications.

1.2 GUARANTEE A. All systems and components supplied under this specification shall be

guaranteed against defective material, poor workmanship, design deficiencies, and failure during normal usage for a minimum of 12 months after the date of acceptance by Engineer. Vendor shall make necessary corrections to all deficiencies noted within this time, without expense to purchaser. Satisfactory warranty documents must be provided.

1.3 STANDARDS AND CODES A. All material and equipment supplied under this specification shall be designed,

assembled, and tested in full compliance with the latest edition of the following codes and standards: 1. NEC - National Electric Code 2. IEEE - Institute of Electrical and Electronic Engineers 3. UL - Underwriters' Laboratories 4. NEMA - National Electronic Manufacturers Association 5. ASA - American Standards Association 6. ANSI - American National Standards Institute

ADDENDUM NO. 2

Acton Municipal Utility District TWDB WWTP No. 1 Improvements Diesel Generator and Controls Project No. 6633 16210-2 July 15, 2020

1.4 All components used shall be UL labeled or listed whenever such recognition is available.

1.5 DRAWINGS AND DATA A. The following items shall be submitted with vendor's proposal:

1. Outline dimensions and weights.

2. Descriptive literature describing the standard series specified (not a

one-of-a-kind fabrication).

3. Drawing submittal schedule with approval allowance requirements.

4. Shipping time after receipt of order.

5. Exceptions and clarifications to this specification.

6. Factory testing procedures.

7. Submit manufacturer’s detailed sizing report indicating compliance with the parameters and load starting sequence as indicated in Section 2.02. Genset size indicated in Section 2.02B is allowed only if manufacturer’s sizing report produced by generator manufacturer’s representative indicates full compliance with all aspects of the parameters and loads listed in section 2.02.

B. The following items are required of the successful bidder prior to manufacture: 1. Certified dimensional drawings showing weight, outline dimensions,

bolting and drilling details, clearances for installation, operation and maintenance, and required ventilation.

2. Elevation views, showing and identifying all items furnished and section views as required to locate all components.

3. Bill of material describing all components and recommended spare parts with pricing and delivery.

4. Brochures on engine, generator, muffler, batteries, charger, fuel tank, control panel, and any accessory equipment showing ratings, construction features, and performance characteristics.

5. Schematic and wiring diagrams of the electrical system showing all factory wiring and clearly indicating wiring and voltage of any electrical strip heaters. Also, submit fully detailed inter-connection drawings indicating each individual connection to any remote equipment, including a separate connection drawing to show point to point electrical wiring connections.

6. Submit documentation indicating compliance with EPA/TCEQ emission requirements for the location and EPA “Tier” rating.

ADDENDUM NO. 2

Acton Municipal Utility District TWDB WWTP No. 1 Improvements Diesel Generator and Controls Project No. 6633 16210-3 July 15, 2020

7. Submit documentation for sound test data, based on free field environment.

1.6 SUBMITTALS AFTER MANUFACTURE A. Factory and Field Tests - Provide each factory and field test report on the

actual packaged electric generating plant provided, indicating results for all tests described herein.

B. Operation and Maintenance Manuals - Two weeks prior to final inspection, provide the manufacturer's operation and maintenance manuals pertaining directly to the unit provided. Include the following information: 1. Project record drawings clearly indicating operating features and

including as-built shop drawings, outline drawings, schematic and wiring diagrams.

2. Instructions for erection and alignment, including tolerances and preparation for use.

PART 2 PRODUCTS

2.1 ACCEPTABLE MANUFACTURERS A. Diesel Engine Driven Generator Set, complete with accessories, shall be:

1. Cummins/Onan 2. Caterpillar 3. MTU Onsite 4. Kohler 5. Taylor Power Systems 6. or Pre-Approved equal.

B. Engine shall be:

1. Perkins 2. Cummins 3. MTU 4. John Deere 5. Volvo

2.2 RATINGS

A. VOLTAGE AND CONNECTION – 480V/277V, 3 Phase, 4 Wire, 60 Hertz, 0.8

Power Factor.

B. POWER – 750KW, 937.5KVA

C. LOADS & STARTING SEQUENCE – Generator set shall be capable of starting the following loads in the sequence shown: 1. Lighting and control loads of 15KVA, single phase.

ADDENDUM NO. 2

Acton Municipal Utility District TWDB WWTP No. 1 Improvements Diesel Generator and Controls Project No. 6633 16210-4 July 15, 2020

2. Lighting and control loads of 75KVA, three phase.

3. Lighting and control loads of 75KVA, three phase.

4. Lighting and control loads of 75KVA, three phase.

5. Two (2) 1 HP motor, 1.15 service factor, variable frequency drive; Two (2) 1/2 HP motor, 1.15 service factor, code letter N, full voltage starting; and One (1) 1/4 HP motor, 1.15 service factor, code letter N, full voltage starting.

6. One (1) 2 HP motor, 1.15 service factor, code letter L, full voltage starting.

7. One 5 HP motor, 1.15 service factor, code letter J, full voltage starting.

8. One 5 HP motor, 1.15 service factor, code letter J, full voltage starting.

9. One 10 HP motor, 1.15 service factor, code letter H, full voltage starting.

10. One 10 HP motor, 1.15 service factor, code letter H, full voltage starting.

11. One 7.5 HP motor, 1.15 service factor, code letter H, full voltage starting.

12. One 10 HP motor, 1.15 service factor, variable frequency drive.

13. One 10 HP motor, 1.15 service factor, variable frequency drive.

14. One 10 HP motor, 1.15 service factor, variable frequency drive.

15. One 10 HP motor, 1.15 service factor, code letter H, full voltage starting.

16. One 10 HP motor, 1.15 service factor, code letter H, full voltage starting.

17. One 10 HP motor, 1.15 service factor, code letter H, full voltage starting.

18. One 10 HP motor, 1.15 service factor, code letter H, full voltage starting.

19. One 10 HP motor, 1.15 service factor, code letter H, full voltage starting.

20. One 10 HP motor, 1.15 service factor, code letter H, full voltage starting.

ADDENDUM NO. 2

Acton Municipal Utility District TWDB WWTP No. 1 Improvements Diesel Generator and Controls Project No. 6633 16210-5 July 15, 2020

21. One 15 HP motor, 1.15 service factor, code letter G, full voltage starting.

22. One 15 HP motor, 1.15 service factor, code letter G, full voltage starting.

23. One 15 HP motor, 1.15 service factor, code letter G, full voltage starting.

24. One 40 HP motor, 1.15 service factor, variable frequency drive.

25. One 40 HP motor, 1.15 service factor, variable frequency drive.

26. One 40 HP motor, 1.15 service factor, variable frequency drive.

27. One 40 HP motor, 1.15 service factor, variable frequency drive.

28. One 40 HP motor, 1.15 service factor, variable frequency drive.

D. Generator shall be capable of starting loads in the above sequence with not more than 20% instantaneous terminal voltage drop, and not more than 10% sustained terminal voltage drop with the specified KVA load at near zero power factor applied to the generator set. See section 1.05 A 7.

E. Generator shall be capable of starting loads in the above sequence with not more than 5% instantaneous terminal frequency drop. See section 1.05 A 7.

F. Site operating parameters shall be 100 ft. altitude and an ambient temperature of 95 degrees F.

G. Contractor will be responsible for verifying generator operations by executing procedures in the generator checklist attached to this specification. The checklist includes a load bank test.

2.3 ENGINE A. Type - Liquid cooled, full diesel compression ignition engine, either naturally

aspirated or turbocharged. 4-cycled engine required, or as approved by the ENGINEER.

B. Rating - Provide an engine with brake horsepower not less than required by the full load rating of the generator, including losses, and with all accessories attached.

C. Speed - The engine speed will be suitable for direct connection to the generator without exceeding engine manufacturer's published curves. Speed must not exceed 1800 PRM.

D. BMEP - The engine BMEP will not exceed 351 PSI, when producing rated load. Piston speed shall be 2250 feet per minute or less.

E. Construction:

ADDENDUM NO. 2

Acton Municipal Utility District TWDB WWTP No. 1 Improvements Diesel Generator and Controls Project No. 6633 16210-6 July 15, 2020

1. Replaceable liners. 2. Two (2) valves per cylinder. 3. Full pressure lube system with crank shaft driven oil pump. 4. Unit injectors. 5. Full flow replaceable oil filter. 6. Primary and secondary fuel oil filters. 7. Replaceable fuel transfer pump suitable for a maximum of 4 feet

suction lift. 8. Oil bath or dry type air intake cleaner.

F. Starting System

1. Heavy duty, battery driven electric starter motor.

2. A fully charged 24 volt lead acid, impact resistant, storage battery or

batteries mounted on the unit. Make battery capacity sufficient for four cranking cycles at firing speed of 10 seconds duration each, with 15 seconds rest periods- Provide all battery cables, connections, electrolyte, and a hydrometer.

G. Cooling System - The generator set will be furnished with a unit mounted radiator having sufficient capacity for cooling the engine when delivering full rated horsepower at the design ambient. The fan is to be engine driven pusher type. An immersion heater shall be furnished in the jacket water system.

H. Exhaust System - High degree, critical-rated muffler with maximum silencing capacity mounted on unit. Include a suitable length of flexible exhaust tubing for mounting between engine and muffler. When V type engines are used, a wye type flex will be furnished. All exhaust equipment and hardware mounted to the exterior of the generator enclosure shall be stainless steel.

I. Fuel System 1. Engine driven, self-priming fuel pump suitable for unassisted transfer

of fuel from the fuel tank to the engine.

2. Subbase fuel tank to be UL 142 listed, double-wall, welded steel, with leak detector system. The tank shall be handled in accordance with current installation instructions provided with the tank.

3. Subbase fuel tank capacity shall be sufficient for 48 hours of continuous operation at full rated load of the generator but not less than 2,500 Gallons.

4. Full flow replaceable element fuel filter.

5. Fuel connection lines between tank and engine.

6. Mechanical fuel level gauge.

7. Lockable fuel fill.

ADDENDUM NO. 2

Acton Municipal Utility District TWDB WWTP No. 1 Improvements Diesel Generator and Controls Project No. 6633 16210-7 July 15, 2020

8. Contractor shall provide all fuel required for use during construction and a full fuel tank at project acceptance.

J. Governor - Provide governor of the electric type, Woodward, Onan or an approved equal, to maintain frequency stability at any constant load, including no load, within plus or minus ¼ percent, and to maintain frequency regulation between no load steady state and full load steady within .5 percent.

K. Battery Charger - A static, solid state type battery charger unit which automatically controls the charge rate. Include a charging rate ammeter, thermal overload circuit and transformer. The charge shall be suitable for operation at 120 volts single phase, 60 Hertz. The maximum charging time to bring the batteries up to full charge will be 12 hours. Mount charger on unit, using adequate vibration devices. Charger shall be of the dual rate type.

L. Emissions – Engines used in proposed generator set to be certified to comply with current US EPA and CARB Mobile Off-Highway emission limits when tested per ISO 8178 D2. Engines used shall also comply with TCEQ air quality regulations at the project location and time of installation.

2.4 GENERATOR A. Type - Furnish a direct coupled, synchronous, brushless type generator with

amortisseur windings, revolving field, exciter, and built-in static rectifier and statically regulated excitation system.

B. Insulation System - Class H, minimum, with temperature rise limited to 105C over a 40C ambient under the application of full plant load conditions.

C. Temperature Rise: 105C.

D. Instantaneous Voltage Dip - Less than 20 percent when sequenced load is applied to the unit.

E. Voltage Stability - Maintain within plus or minus 1 percent of rated voltage at any constant from no load to full load.

F. Voltage Regulation - Maintain within plus or minus 1 percent deviation from rated voltage between no load steady state and full load steady state.

G. Coupling - From engine, drive rotor through a semi-flexible coupling to ensure permanent alignment.

H. Strip Heaters - Provide thermostatically controlled, low surface temperature space heaters to prevent condensation.

I. Generator Set Control and Protection - Provide comprehensive monitoring and control system integral to the Generator Set control to guard the electrical integrity of the alternator and power system. Provide single and 3-phase fault current regulation, so that downstream protective devices have the maximum current available to quickly clear fault conditions, without subjecting the alternator to potentially catastrophic failure conditions. Include provisions to either prevent over voltage due to single phase faults, or to shut down the

ADDENDUM NO. 2

Acton Municipal Utility District TWDB WWTP No. 1 Improvements Diesel Generator and Controls Project No. 6633 16210-8 July 15, 2020

generator set if line to neutral voltage on any phase exceeds 115% for more than 0.5 seconds. Submittals shall demonstrate that the protective device provides proper protection for the alternator by a comparison of the trip characteristic of the breaker with the thermal damage characteristic of the alternator. Field circuit breakers shall not be acceptable for generator overcurrent protection.

2.5 CONTROL PANEL A. General - Provide a control panel mounted to unit which includes, but is not

limited to, the following instruments and protective devices. 1. AC ammeter.

2. Phase selector switch.

3. Current transformers.

4. AC voltmeter.

5. Automatic solid state voltage regulator.

6. Rheostat for adjusting voltage plus or minus 5 percent of rated voltage.

7. Engine Malfunction Warning Lights:

a. Low oil pressure. b. High water temperature. c. Engine overcrank. d. Engine overspeed.

8. Frequency meter.

9. Non-resettable elapsed time meter with a 9,999.9 hour maximum

indication.

10. Coolant temperature gage.

11. Oil pressure gage.

12. 100% rated main circuit breaker with adjustable trip settings. For breakers rated 1,000A and larger, provide a ground fault indication alarm. Alarm shall be wired to generator controller to trigger a generator general fault alarm to notify operations staff. Provide a second output circuit breaker if shown on construction drawings. Second output breaker shall be 100% rated with adjustable trip settings. For breakers 1,000A and larger, provide a ground fault indication alarm. Alarm shall be wired to generator controller to trigger a generator general fault alarm to notify operations staff.

ADDENDUM NO. 2

Acton Municipal Utility District TWDB WWTP No. 1 Improvements Diesel Generator and Controls Project No. 6633 16210-9 July 15, 2020

13. Combination alarm-shutdown system with manual reset and indicating lights for high engine temperature, low oil pressure, engine overspeed, and engine fail-to-start. Include an additional set of contacts for remote alarms.

14. Manual start/stop switch for control of engine.

15. Alarm dry contact closures as follows: a. Low oil pressure b. High water temperature c. Engine overcrank d. Engine run e. Fuel low level f. Leak in subbase tank g. General failure alarm for any active generator/fuel tank alarm

16. Remote control contacts as follows: Engine start via transfer switch

(which will include power transfer).

17. Provide latest electronic control panel at engine and with remote control panel at transfer switch. Remote panel to have full functions.

B. All interface wiring connections shall be made in the control panel.

C. Control panel heater - Provide thermostatically controlled, low surface temperature space heaters to prevent condensation.

D. Remote alarm annunciator – Comply with NFPA 110. An LED labeled with proper alarm conditions shall identify each alarm even and a common audible signal shall sound for each alarm condition. For outdoor annunciator installations, install the annunciator inside the automatic transfer switch with a viewing window or in a metal enclosure with a viewing window and sun shade of the same NEMA rating as specified for the automatic transfer switch.

E. Generator shall include Modbus TCP/IP communications protocol for integration of generator with Owner’s control system. Provide RJ-45 ethernet connection. Where necessary, contractor shall provide serial to ethernet convertor.

2.6 ENGINE START/STOP CONTROLS A. The engine controls shall be provided with bypassing of the low oil pressure

shutdown circuitry during start-up.

B. If unit fails to start in an appropriate time (normally 30 seconds), the starting circuit shall shut down for an appropriate time (approximate 10 seconds) and then repeat the start cycle. If the unit still fails to start after approximately four start attempts, the overcrank alarm shall activate and the starting circuit shall shut down.

C. The engine start/stop control shall be static solid state.

ADDENDUM NO. 2

Acton Municipal Utility District TWDB WWTP No. 1 Improvements Diesel Generator and Controls Project No. 6633 16210-10 July 15, 2020

2.7 BASE A. Mount the assembled packaged unit on a base of welded structural steel, box

type construction. Prime all exposed metal parts with a rust inhibitor and finish in durable machinery enamel (Design for mounting on subbase tank).

B. Vibration isolators shall be provided with elastomeric isolator pads integral to the generator, unless the engine manufacturer requires the use of steel spring isolation.

2.8 WEATHERPROOF SOUND ATTENUATING HOUSING The enclosure shall meet the following criteria: rigidity wind test equal to 100 MPH (ASCE 7-05, Exposure C), roof load equal to 40 lbs. per sq. ft., and rain test equal to 4” per hour. A. Construction

1. Provide an overall weatherproof prefabricated drop over sound

attenuating steel enclosure. Instruments, controls, and battery system shall be mounted within enclosure.

2. Doors – Hinged with padlocking provisions. Restraint/Hold back hardware to keep door open at 180 degrees during maintenance. Rain lips over all doors.

3. Panels – Removable side panels, when equipped, shall be lockable and provide adequate access to components requiring maintenance.

4. Louvers – Equipped with bird screen to permit air circulation when engine is not running while excluding bird and rodents.

5. Hardware – All hardware and hinges shall be stainless steel.

6. Mounting Base – Suitable for mounting on sub-base fuel tank or housekeeping pad.

B. Engine Cooling 1. Housing shall provide ample airflow for engine generator operation at

rated load in an ambient temperature of 40 deg C. The enclosure shall not exceed the generator manufacturer’s recommendations for total external static pressure to ensure adequate airflow for cooling and combustion.

C. Sound Performance 1. Reduce the sound level of the engine generator while operating at full

load to a maximum of 75 dBA measured at any location 23 feet (7 meters) from the engine generator in a free field environment.

ADDENDUM NO. 2

Acton Municipal Utility District TWDB WWTP No. 1 Improvements Diesel Generator and Controls Project No. 6633 16210-11 July 15, 2020

D. Painting 1. Prime all exposed metal parts with a suitable rust inhibitor applied to

the clean, bare metal, followed by two coats of an epoxy paint of powder-coated and baked for exterior weather.

E. Site Provisions 1. The complete assembly of engine generator, enclosure, and sub based

fuel tank (when applicable) shall be designed to be lifted into place as a single unit.

F. Interior Lighting 1. For generators 150kW and larger, provide two (2) 120V fluorescent

strip, compact fluorescent, or LED fixtures rated vapor-tight and for wet location. Provide two (2) 3-way switches, one on each side.

G. Lighting Panelboard – For generators larger than 200 kW or when indicated on the drawings, provide a factory installed 120/240 Volt, single-phase panelboard with a minimum main breaker rating of 60 Amps inside the generator enclosure. The panel shall be mounted in accordance with NEC working space requirements. All generator 120/240 Volt components shall be factory wired to the panelboard.

H. Receptacle – Provide one (1) 125V, 20A, Duplex GFI receptacle in a weatherproof FS box with a weatherproof cover mounted internally to the enclosure. The receptacle shall be mounted in accordance with NEC requirements. The circuit shall be wired locally when a single-phase panelboard is provided with the generator.

I. Contractor to coordinate with manufacturer on housing size prior to constructing concrete pad.

2.9 TESTING A. Units shall be factory tested under design conditions. Purchaser, at his option,

may witness test. Vendor shall give one (1) week notice before test is made.

2.10 FIELD TESTS A. Perform field tests at the site after installation is complete and in the presence

of the Owner’s representative.

B. Perform sequence start-up of plant and demonstrate compliance with specifications.

C. Perform on site resistive load bank testing to the full capacity of the generator set for a minimum of two (2) continuous hours. Verify adequate generator cooling, fuel flow, metering, and operation. Contractor shall contact Engineer at least 48 hours prior to commencement of testing.

ADDENDUM NO. 2

Acton Municipal Utility District TWDB WWTP No. 1 Improvements Diesel Generator and Controls Project No. 6633 16210-12 July 15, 2020

2.11 TRAINING A. The equipment supplier shall provide training for the facility operating

personnel covering operation and maintenance of the equipment provided. The training program shall be not less than 4 hours in duration and the class size shall be limited to 3 persons. Training date shall be coordinated with the facility owner.

2.12 SERVICE AND SUPPORT A. The manufacturer of the generator set shall maintain service parts inventory

at a central location which is accessible to the service location 24 hours per day, 365 days per year.

B. The generator set shall be serviced by a local service organization that is trained and factory certified in generator set service. Within 50 mile of the job site, the supplier shall maintain; a minimum of 6 factory trained and qualified field technicians; a proper supply of spare parts for the supplied equipment; a shop with overhaul capabilities; and be able to provide 24 hour, 7 day per week, 365 day per year field service capability.

C. The manufacturer shall maintain model and serial number records of each generator set provided for at least 20 years.

END OF SECTION