Regulatory Issues Associated With Pile Driving

7/27/2019 Regulatory Issues Associated With Pile Driving

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Regulatory Issues associated

with Pile Driving


2/22

WSDOT Structures

19 Ferry

Terminals

2,000

bridges over

water


3/22

Complex Regulatory Environment for

In -water Pile Driving

Three main regulatory agencies

Washington Department of Fish and Wildlife

US Fish and Wildlife Service

National Marine Fisheries Services


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Three main regulations: State Hydraulic Project Approval sets in water work

window to protect fish life.

Endangered Species Act: prohibits take of listed

species without incidental take permit. Administered by both USFWS terrestrial species and bull

trout

NMFS for marine Species

Marine Mammal Protection Act: Prohibits take ofmarine mammals without a permit. Administered by NOAA NMFS but a different section from

the ESA section.


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Endangered Species Act Protected SpeciesPresent in Puget Sound and potentiallyimpacted by in-water pile driving :

Marbled murrelet Listed fish species including bull trout, 3 listed

salmonid species, rock fish (3 listed species), greensturgeon and eulachon.

Two listed cetaceans : SR killer whales, andhumpback whales.

One listed pinniped : Stellers seal lions.


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Marine Mammal Protection Act:

Protected Species potentially present in Puget

Sound include 31 species of pinnipeds and

cetaceans.


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In 2002 WSDOT and California DOT

documented their first instance of a fish kill

associated with impact pile driving of steelpiles.


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The USFWS and NMFS identified thresholds

for impact underwater pressures that they

felt would result in injury or harm and

thresholds that they felt would result in

disturbance or harassment.

Pile driving activities that would expose

listed species to sounds above these levels

could result in take and would require aincidental take permit.


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Species Injury Threshold Disturbance

Threshold

Fish > 2 grams 206 dBpeak

and

187 SELcum

150 dBRMS

Fish < 2 grams 206 dBpeak

and

183 SELcum

150 dBRMS

Diving marbled murrelet 180 dBpeak 150 dBRMS

Whales 180 dBRMS 160 dBRMS

Steller sea lion 190 dBRMS 160 dBRMS

These are the underwater thresholds are set for impulse

sounds like those generated by impact pile driving.


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The Practical Spreading model is used to

determine how far out the impulse soundassociated with pile driving travels.

The model is also used to determinewhere the zone of injury and disturbance

extends to .


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Distance (m) to threshold

Onset of Physical Injury Behavior

Peak Cumulative SEL dB** RMS

dB Fish 2 g Fish < 2 g dB5 172 318 2154


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Distance (m) to threshold

Onset of Physical Injury Behavior

Peak Cumulative SEL dB** RMS

dB Fish 2 g Fish < 2 g dB

5 172 318 2154


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In addition to identifying thresholds, the

Services and WSDOT have developed

minimization measures. Applying timing restrictions doing work when listed species were not

likely to be present.

Monitoring for the presence of listed species during pile driving and

shutting down the work when the listed species entered the zone ofdisturbance ( only possible for pinnipeds, cetaceans and marbled

murrelets).

Using bubble curtains during impact driving to reduce sound levels

and alter the pressure wave to minimize and/or avoid take.

Using vibratory hammers to avoid impulse sounds, thus avoiding takeof listed fish and murrelets.


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More Recently

NMFS has been

implementing avibratory pile

driving

disturbance

threshold of

120 dB RMS formarine

mammals.

Practical Spreading

Model

SPL

RMS)

= 177 177

Distance= 10 10

160 dB

RMS

120 db

RMS

Meters = 136 63096

Miles = 0.08 39.21


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Keystone

160 DBRMS

Threshold

Calculatedwith the

Practical

SpreadingModel


16/22

Keystone

120 DBRMS

Threshold

Calculatedwith the

Practical

SpreadingModel


17/22

Another area of noise concern is in air

thresholds for noise disturbance:

100db RMS for Sea lions

Photo by WSF


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What are some of the issues associated

with consultations involving pile driving?

How can we accurately predict the extent of

noise impacts?

What are the limitation of the noise models?

How well do they predict sound attenuation ?

( model verification)

How can we achieve agreement on the

appropriate noise model between and withinagencies?


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What are the background underwater noise

levels in Puget Sound?

What is the most appropriate sampling design for

determining background underwater noise levelsgiven the limited in-water work window?

What is the most appropriate sampling design for

Puget Sound? How should ambient or background levels be

defined?


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Can the level of attenuation achieved by a

sound pressure attenuation device be

accurately predicted?

How effective is monitoring and shutting

down pile driving at prevent impacts to

protected species?

Is it cost effective for the project?

Is it protective to the species?


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What other methods could be used to prevent

impacts to protected species?


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Questions?

Photo courtesy of USFWS

Regulatory Issues Associated With Pile Driving

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