MLA/2015/00336 HMNB Devonport Maintenance Dredging and Disposal

Water Framework Directive (Council Directive 2000/60/EC) Assessment February

2016

Stage One: Screening

Part A

Step 1: Was the maintenance dredging and/or disposal carried out during the period

2006-2008?

Yes: Dredging activities, and associated disposal, have been carried out

under the FEPA licensing regime since 1985.

Step 2: Collate information about the dredging or disposal activity (Table 1); and

Identify the water body(s) the activity(s) may affect and its ecological and

chemical status (Table 2)

Table 1: Dredging and disposal information required to inform screening process

Dredging Disposal

Location of proposed dredging or disposal activity: • Describe location(s) or provide grid reference or other coordinates. • Dredge footprint. • Dredge depth. • Dredge timing and duration (proposed). • Dredge methodology. • Dredge/disposal volume.

Location (including footprint and depth) provided in Figure 1; co-ordinates provided in Annex 1. The approximately dredge depth is -9m CD. Footprint of dredge area is approximately 253,135m

2

Proposed timing and duration: 1 February 2016 to 31 March 2017 (two main campaigns with additional minor dredging throughout the year (subject to seasonal restrictions)) Methodology: TSHD to be used; Smaller vessels may be use where access if difficult for TSHD. Plough dredging will also be undertaken for bed levelling and submersible pumps may be employed in areas which are inaccessible to other dredging methods. A full methodology is included in Annex 2. Dredge volume: up to 63,448m

3

Location: PL031 (Rame Head South); co-ordinates provided in Annex 2. Footprint of disposal site is approximately 253,135m

2

Proposed timing and duration: as dredging Methodology: Bottom dumping from TSHD to south-west corner of disposal site. A full methodology is included in Annex 2. Disposal volume: up to 63,448 m

3

Above information relating to any previous dredging and disposal activities at that location.

Number of years dredging that has been carried out using the methodology stated above: 31 Average number of dredging campaigns that have been carried out per year: 2 Maximum volume of material that has been dredged per campaign (m3): 46500 Maximum volume of material that has been dredged per year (m3): 75500

OSPAR disposal returns for Rame Head (PL031) date back to 1994. Prior to this disposal activity was undertaken but regulated under FEPA 1985. Disposal returns are included in Annex 3.

Sediment quality data (available from MMO or CEFAS if a marine licence application has previously been made).

Sediment quality data is included in Annex 4.

Protected areas in or close by the activity (• areas designated under the EC Birds and/or Habitats Directives; • areas designated under the EC Shellfish Directive and Freshwater Fish Directive; • areas designated under the EC Bathing Waters Directive; • areas designated

Plymouth Sound and Estuaries SAC - dredging area is within this designated site

Tamar Estuaries Complex SPA - within 1.7km from dredging zone, at nearest point

Start Point to Plymouth Sound and Eddystone SCI - >10km from dredging area

Plymouth Hoe East Bathing Water c5km from dredging zone

Plymouth Hoe West Bathing Water c5km from dredging zone

Start Point to Plymouth Sound and Eddystone SAC - is over >10km from both activity sites

Plymouth Sound and Estuaries SAC -disposal area is within 1.9km of designated site

Start Point to Plymouth Sound and Eddystone SCI - >10km from disposal site

Whitsand (Sharrow) Bathing water – 3.5km from disposal site

under the EC Nitrates Directive or Urban Wastewater Treatment Directive.)

Was this dredging and/or disposal activity carried out during the period 2006–2008? – if no, go to New Project process – if yes, continue. Do one or more of the following (area, volume, method and timing of the dredging or disposal activity) differ significantly from that carried out during 2006–2008? – if yes, go to New Project process – if no, continue.

Yes No

Yes No

Is there any evidence that indicates that maintenance dredging or disposal activities could lead to deterioration in the status of the water body or delay or otherwise affect the future ability of the water body to meet good status?

No – dredging and disposal activities have been ongoing since before the implementation of the South West River Basin Management Plan in 2009

Is the water body (or are the water bodies) already at good status (see Table 2)? – if yes, go to step 5 – if no, continue.

Yes – see table 2

Could dredging or disposal activities affect or have affected the status of the water body (or water bodies)? – if yes, go to Part B – if no, continue.

No - dredging and disposal activities have been ongoing since before the implementation of the South West River Basin Management Plan in 2009

Are there any (additional) cost-effective, technically feasible and not disproportionately costly dredging- or disposal-related measures that would contribute to a meaningful improvement in the status of the failing parameters at water body level?

Standard TSHD procedures will be used and conditions can be applied to any marine licence to minimise impacts of dredging. The methods permitted would be limited to those that prevent the overflowing of the hopper, as far as reasonability practicable. It is considered that any unavoidable overflow of the hopper would only result in short term and temporary effects.

Activity currently Yes

complies with WFD objectives?

Table 2: Water Body Information

Water Body Name PLYMOUTH SOUND PLYMOUTH OUTER PLYMOUTH COAST

Water Body ID GB520804714300 GB650806230000 GB620806110003

River Basin District South West South West South West

Typology Mixed, meso,

extensive intertidal

Moderately exposed, Mesotidal

Exposed, Mesotidal

Hydromorphological

Status

Heavily Modified Heavily Modified Not Designated A/HMWB

Current Ecological

Quality

Good Potential Good Potential Good Status

Current Chemical

Quality

Fail Does Not Require Assessment

Does Not Require Assessment

2015 Predicted

Ecological Quality

Good Potential Good Potential Good Status

2015 Predicted

Chemical Quality

Fail Does Not Require Assessment

Does Not Require Assessment

Overall Risk At Risk At Risk Probably At Risk

Protected Area Yes Yes Yes

Number of Measures

Listed

(waterbody level only)

29 6 6

Data from http://maps.environment-agency.gov.uk/wiyby/ [accessed 29 January 2015)

Step 3: Have there been:

Any significant changes to characteristics of the dredging (e.g. methodology,

dredge area, dredge depth, volume, timing or disposal method)

No

Any known pollution events since dredging was last carried out?

No pollution events have occurred since the last Trailer Suction Hopper

Dredge which was last carried out in 2014. (Reference:

http://maps.environment-agency.gov.uk/wiyby/ [accessed 26 January

2016])

Is there any indication that dredging is contributing to failures of protected

areas to meet their objectives?

No; due to distance from dredge and disposal sites to protected areas.

Step 4: Is the water body at good chemical status and good ecological status or

good ecological potential?

No: Plymouth Sound is not at good chemical status

Conclusion from Part A

Based on information presented within Steps 1-4, assessment must continue to Part B in

relation to the chemical status of Plymouth Sound.

Figure 1: Dredge Location, footprint and depths

Part B

Step 1-2: Identify which parameters are failing to meet their WFD objectives. For each

of the failing parameters (including protected areas) does the RBMP identify

dredging as a cause of the failure of any of (including protected areas)?

For each failing parameter, where dredging/disposal is not listed on the

RBMP as a cause of failure, use the criteria listed in the Trigger Table to

identify if dredging/disposal is considered to be a potential cause of failure.

Step 1-2 therefore requires completion for following Water Bodies:

Plymouth Sound (GB 650806230000); failing parameter chemical quality

Table 3b: Information on water body chemical status

Water Body: Plymouth Sound (GB650806230000)

Information required on WFD chemical status

Source or link

Current chemical status Fail

2015 chemical status objective Unfavourable balance of cost and benefits; disproportionately expensive

Priority and priority hazardous substances not meeting WFD objectives

Tributyltin Compounds

Activities, etc. causing failure(s)

N/A – historic use of TBT within shipbuilding.

Any links to dredging and disposal?

No. Sediment samples analysed from HMNB Devonport do not show TBT levels above acceptable limits. Sediment sample analysis is included at Annex 4.

Step 3: Based on the information presented within Table 3, it can be concluded that

dredging and disposal is unlikely to be a potential cause of failure.

There are no cost-effective, technicaly viable and not disproportionately

costly dredging or disposal-related measures that would contribute to a

meaningful improvement in the status of the failing parameters (chemical –

TBT) at water body (Plymouth Sound) level. (Reference:

http://environment.data.gov.uk/catchment-

planning/WaterBody/GB650806230000 [accessed 29 January 2016])

Step 4: Based on the outcomes of steps 1-3 above, no further WFD assessment is

required.

Annex 1: Coordinates for dredge location

Dredge Area NY10

50°23.3106'N 04°11.4230'W

50°23.3116'N 04°11.4262'W

50°23.3109'N 04°11.4295'W

50°23.3017'N 04°11.4251'W

50°23.2893'N 04°11.4194'W

50°23.2931'N 04°11.4176'W

50°23.2945'N 04°11.4150'W

50°23.2964'N 04°11.4054'W

50°23.3006'N 04°11.4072'W

50°23.3016'N 04°11.4077'W

50°23.3066'N 04°11.4100'W

50°23.3116'N 04°11.4125'W

50°23.3103'N 04°11.4210'W

50°23.3106'N 04°11.4230'W

Dredge Area NY1/NY2/NY3/NY4/NY7/NY8

50°23.5780'N 04°11.2513'W

50°23.5841'N 04°11.2186'W

50°23.6087'N 04°11.2299'W

50°23.6032'N 04°11.2626'W

50°23.5991'N 04°11.2607'W

50°23.5242'N 04°11.6585'W

50°23.5210'N 04°11.6735'W

50°23.5477'N 04°11.6855'W

50°23.5396'N 04°11.7285'W

50°23.5307'N 04°11.7727'W

50°23.5147'N 04°11.7938'W

50°23.4980'N 04°11.7893'W

50°23.4704'N 04°11.9336'W

50°23.4006'N 04°11.8005'W

50°23.3800'N 04°11.7609'W

50°23.3331'N 04°11.6712'W

50°23.2943'N 04°11.5967'W

50°23.2778'N 04°11.5650'W

50°22.9656'N 04°11.4181'W

50°22.9785'N 04°11.3484'W

50°22.9824'N 04°11.3293'W

50°23.1386'N 04°11.4024'W

50°23.2119'N 04°11.4370'W

50°23.2927'N 04°11.4737'W

50°23.3109'N 04°11.4821'W

50°23.3432'N 04°11.5418'W

50°23.3794'N 04°11.6129'W

50°23.4005'N 04°11.6542'W

50°23.4259'N 04°11.6216'W

50°23.4054'N 04°11.5822'W

50°23.4592'N 04°11.5134'W

50°23.5166'N 04°11.2143'W

50°23.5193'N 04°11.2157'W

50°23.5478'N 04°11.2275'W

50°23.5742'N 04°11.2397'W

50°23.5725'N 04°11.2487'W

50°23.5780'N 04°11.2513'W

Annex 2: Coordinates for Rame Head South disposal site

50°18.5100'N 04°15.1980'W 50°18.9000'N 04°15.1980'W 50°18.9000'N 04°16.4880'W 50°18.4020'N 04°16.7999'W 50°18.5100'N 04°15.1980'W

Annex 2: Dredging and Disposal Methodology

Annex 3: Rame Head Disposal Returns

PL031 Wet Tonnes

DispSiteCode DispYear SumOfDispQty

PL031 1994 126058

PL031 1995 478976

PL031 1996 13125

PL031 1997 327364

PL031 1998 46760

PL031 1999 64031

PL031 2000 114859

PL031 2001 1095071

PL031 2002 11984

PL031 2003 94280

PL031 2004 241704

PL031 2005 140321

PL031 2006 0

PL031 2007 98883

PL031 2008 24538

PL031 2009 38598

PL031 2010 77582

PL031 2011 11480

PL031 2012 104228

PL031 2013 60398

PL031 2014 73198

Annex 4: Sediment Quality Data