rehabilitating the north coast water main · 2017-06-01 · technologies seminar february 23, 2017...

PUG – 25TH ANNUAL SHARING TECHNOLOGIES SEMINAR

FEBRUARY 23, 2017

PHASE 3 AND THE EMERGENCY INSTALLATION AT LOMBARDI GULCH

REHABILITATING THE NORTH

COAST WATER MAIN

Presentation Outline

03/03/2017 2

1. Overview of Santa Cruz system

2. Planning and design of the North Coast Segment

3. Emergency HDD installation at Lombardi Gulch

1. Design 2. Construction

4. Current status of North Coast Rehabilitation

Speaker: Justin Lianides, PE - Mott MacDonald

25th Annual Sharing Technologies Seminar – PUG | North Coast System Rehabilitation

100 Years

03/03/2017 3 25th Annual Sharing Technologies Seminar – PUG | North Coast System Rehabilitation

Service Area Characteristics

Areas Served:

Santa Cruz

County

Capitola

Population:

~ 93,000

Employment:

~ 45,000

Governing body: City Council


03/03/2017 5

2.8-billion gallon Capacity

North Coast Resources

[~32%], Acq. 1884-1913

Total Watershed ≈ 21 mi2

San Lorenzo River

[~47%], Total Watershed ≈ 138 mi2

[~4%]

100% FROM LOCAL RAINFALL

95% SURFACE WATER, 5% WELLS

[~17%]

, Est. 1924

Est. 1976

Est. 1960


03/03/2017 6

10-YR PRODUCTION BY SOURCE


Primary Santa Cruz Problem: Lack of Adequate Water Supply During Drought

Additional Challenges: Fish Flows

-

50,000

100,000

150,000

200,000

250,000

300,000

19

21

19

23

19

25

19

27

19

29

19

31

19

33

19

35

19

37

19

39

19

41

19

43

19

45

19

47

19

49

19

51

19

53

19

55

19

57

19

59

19

61

19

63

19

65

19

67

19

69

19

71

19

73

19

75

19

77

19

79

19

81

19

83

19

85

19

87

19

89

19

91

19

93

19

95

19

97

19

99

20

01

20

03

20

05

20

07

20

09

20

11

20

13

20

15

Tota

l An

nu

al R

un

off

(ac

re-f

eet)

Water Year

WATER YEAR CLASSIFICATION SYSTEM San Lorenzo River

Wet Normal Dry Critically Dry

Average Annual Runoff:

93,000 acre-feet


$0

$5,000,000

$10,000,000

$15,000,000

$20,000,000

$25,000,000

$30,000,000

$35,000,000

$40,000,000

$45,000,000

$50,000,00010-YEAR CIP SUMMARY

Rehab or Replace

Upgrade or Improve

Water Supply Reliability

$169 M $127M


HISTORY OF THE NORTH COAST SYSTEM

03/03/2017 9

1880’s

First municipal source of water

2000’s

Numerous repairs, and

environmental conditions

prompted planning and EIR for

replacement of entire system.

1950’s

Major sections of the system

were reconstructed (by Granite)

1916

Competing water companies

consolidated under municipal

ownership

Present


NORTH COAST SYSTEM REHABILITATION PROJECT

Phase 3

(2016-2017)


Phase 2

(2012) Phase 1

(2008)

Majors Creek

Laguna

Creek

Liddel

Spring

GENERAL NORTH COAST CONDITIONS

03/03/2017 11

Agricultural

Fields

Santa Cruz

Branch Rail Line

Highway 1

Pacific

Ocean

Santa Cruz Mountain

Foothills

Copyright © 2002-2015 Kenneth & Gabrielle Adelman

Land Owners

55% CA State Parks

25% SCCRTC

17% Caltrans

3% Graniterock Inc.


82%

1%

13%

4%

24-in PVC - 14,835 ft

6-in PVC - 730 ft

16-in PVC - 2,275 ft

18-in PVC - 220 ft

NEW WATER MAIN Phase 3

03/03/2017 12

Total of 18,060 feet


Lombardi Gulch HDD,

Length 1300 ft

NEW MAIN ALIGNMENT North Coast System Rehabilitation Phase 3

03/03/2017 13

Major’s Line @ Hwy1

HAB, Length 192 ft Service Lateral #1 @ Hwy1

HAB, Length 233 ft

Western Rail Crossing

HAB, Length 127 ft

Eastern Rail Crossing

HAB, Length 82 ft

2000 ft

City of Santa Cruz Project Vicinity


BIOLOGICALLY SENSITIVE AREAS IN PROJECT VICINITY


California red-legged frog

Federally Threatened

Western pond turtle

Species of Concern

Western burrowing owl

Species of Concern

Ohlone tiger beetle

Critically Imperiled

Other Species

Steelhead, Coho Salmon, Tidewater

Goby, and other migratory birds

PRINCIPLE GEOLOGIC UNITS

03/03/2017 15

Santa Margarita Sandstone (Tsm) - Miocene-age shelf deposit

Santa Cruz Mudstone (Tsc) - Miocene-age deep calm water deposit

Marine Terrace Deposits (Qcl) - Deposited during retreat of sea during inter-glacial period 75,000 years ago.

Alluvium – backfilled stream valleys beginning 15,000 years ago + Colluvium, Artificial Fill


EXPLORATORY BORING PROGRAM (Completed Feb. ‘13)

Phase 3

03/03/2017 16

Monterey Bay

Drilling Method Quantity Mud Rotary 5

Mud Rotary/Rock Coring 11

Rock Coring 1

Hollow Stem Auger (HSA) 5

HSA/Rock Coring 1

Hand Auger 2

Average Boring Spacing 780 ft

Average Boring Depth 35 ft

Number of borings 25

Total boring footage 816 ft

Feet drilled / Lpipeline 5%

0

20

40

60

80

100

120

Dep

th (

ft)

Borings Depths


+600 ft of Geophysics

PROJECT SUMMARY PHASE 3 - North Coast Rehabilitation

03/03/2017 17

ORIGINALLY SCHEDULED

TO BID IN EARLY 2016 $7.2 Million

Engineer’s

Estimate

Phase 3

630 ft

Four Horizontal Auger Bore

(HAB) Installations

1,400 ft

One (1) Horizontal Directional

Drill (HDD) Installation

16,000 ft

Trenched Installations


TRENCHLESS

TRENCHED

3.4 MILES OF NEW

WATER MAIN

LEAK IN EXISTING PIPELINE Oct. 2015

03/03/2017 18

Lombardi Gulch HDD

Alignment Parallel to Existing Main Existing Steel Pipe

• Occurred several months prior

to planned bidding

• 22 in. welded steel pipe

leaking at 500,000 gallons/day


BIDDING AND PROCUREMENT

Pipe Rupture

03/03/2017 19

Ph

as

e 3

[1s

t C

on

trac

t] Emergency HDD Installation

LOMBARDI GULCH

$1.27 Million The HDD Company &

Underground Solutions

Trench and HAB

Installations

$5.1 Million Granite Construction

Advertised

Oct. 2015


100% DESIGN

@ Lombardi Gulch

*Secured ahead of advertisement

• $190,000 FPVC pipe (~$135/ft w/ fuse)*

• $1,080,000 HDD Installation (~$830/ft)

w/ All-State Boring

(Subcontractor for HAB)

Ph

as

e 3

[2n

d C

on

trac

t]

• ~$307/ft w/ 4 HAB

Advertised

Mar. 2016

CM: The Covello Group

LOMBARDI GULCH HDD OVERVIEW

Length

1,320 feet

Final Reamed Diameter

36 inches

Installed Carrier Pipe

24-in DR 18 (235 psi) Fusible PVC |

1.43” wall | 307,000 lb safe pull force

Site Conditions

Alluvium-filled valley with stream

channel inhabited by threatened

California Red-legged frog

03/03/2017 20

Antecedents

Existing pipe rupture required

emergency procurement and

installation

Number of Bids

2

Contract Award

The HDD Company, for $1.27 Million

Installation Duration

~2.5 months (Oct. 2015 – Jan, 2016)


INTERPRETED GEOLOGIC CONDITIONS

With HDD Alignment

03/03/2017 21

ENTRY PIT EXIT PIT

PLAN

PROFILE

1000 ft


ROCK IN VICINITY OF LOMBARDI GULCH


Mudstone

Overburden

Soils

WEATHERED

BEACH CLIFFS

ALLUVIAL DEPOSITS IN LOMBARDI GULCH


Gravel w/ clay @ 44-47 FT DEPTH

Gravel w/clay @ 36-44 FT DEPTH

Silty Sand @ 25 FT DEPTH

Sand w/ Silt @ 90 FT DEPTH

Layout of Alignment

• Entry and exit locations, Drive length, Geologic and geotechnical considerations, Clearance from existing infrastructure / resources, Land Ownership / Permitting: CA State Parks (Right-of-Entry), US Fish&Wildlife,

Geotechnical Considerations

• Hydraulic Fracturing (aka frac-out) risks: Where drilling fluid pressures in a borehore exceed the strength and confining ground pressures. Results in a loss of fluid into ground mass, possibly to ground surface.

Pipe installation Stresses

• Pull-back, Breakover of PVC

Design Considerations

Subtitle


CONSTRUCTION

OF THE

LOMBARDI

GULCH

EMERGENCY

HDD CROSSING


HDD BASICS


HDD ALIGNMENT AND FRAC-OUT RISKS


020,00040,00060,00080,000

100,000120,000140,000160,000

144+00 146+00 148+00 150+00 152+00 154+00 156+00

Station (ft) preq pminFRAC-OUT Risks

Pressure (psf)

Preq - maximum allowable pressure in hole

Pmin – minimum drilling fluid pressure

HDD STAGING AREAS


Rig

Sid

e

Pip

e S

ide

Two Pipe Strings

RIG#1: INITIAL 8-¾” PILOT HOLE AND REAMING

DITCH WITCH JT 80/20 106,000 LBS. (PULLBACK) / 70,000LBS. (THRUST)


RIG#2: FINAL 36” REAMING, SWAB AND PIPE PULL AMERICAN AUGERS 380,000 LBS. (PUSH&PULL)


MUD SEPARATION PLANT


HDD INSTALLATION PROGRESS


NTP: 11/3/2015

Estimated Completion Date:

12/17/2015

Actual Completion Date:

1/6/2016

Additional Completion Days:

15 Calendar Days due to

Inadvertant Drilling Fluid

Release (IDFR)

IDFR MITIGATION MEASURES


TEMPORARY DIVERSION OF LOMBARDI GULCH

Perimeter of silt fences, gravel bags, and wattles, removed from the gulch in several 20-gallon containers; later to separation plant

HYDROSTATIC PRESSURE TESTING


CARRIER PIPE PULLBACK


Mid-pullback Fuse

Pull Forces between 48 and 55 kips

PULL THROUGH AND TIE-IN


Pull-Through

Tie-in

RESTORATION OF ECOSYSTEM AT LOMBARDI GULCH


Part of Section 1600 Lake and Streambed Alteration Permit

California Department of Fish and Wildlife

+ removal of existing surface pipe

CONSTRUCTION OF THE

REMAINING PHASE 3 - NORTH

COAST SYSTEM REHAB PROJECT


May 2016 -

Present

CONSTRUCTION OF PHASE 3 [2ND CONTRACT] Project Status


CONSTRUCTION OF PHASE 3 [2ND CONTRACT] Auger Bores (36” Dia.) under Highway 1


Crossing 1 (PP1): 192 FT

Crossing 2 (PP2): 233 FT

NORTH COAST ACCOMPLISHMENTS

• HDD resulted in fewer environmental disturbances (compared to

trenching), to the sensitive ecosystem along the creek. This is despite

IDFR and remediation work.

• A successful HDD intersect maintained project schedule for the pilot

bore while mitigating surface IDFR. Benefited from the steering tool

system and experience of the steering hand.

• Large volumes of drilling fluid (~2000 gal. over 1,000 - 2,000 ft2) during a

frac-out were effectively contained in accordance with a submitted

Frac-out and Surface Spill Contingency Plan.

• The emergency leak and accelerated construction schedule benefited

from good working relationships between the SCWD, Contractor, CM,

Designer, Biologists, and Agencies. Relationships were tested during

IDFR mitigation.

• The pipeline through Lombardi Gulch was successfully put into

operation following the installation. The site has been restored with

additional riparian-native plants.

• SCWD is nearly complete in rehabilitating a deteriorating water main

for the North Coast sources.


Thank you

PUG 25th Annual Sharing Technologies Seminar


rehabilitating the north coast water main · 2017-06-01 · technologies seminar february 23, 2017...

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