In situ remediation projects

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During Spring and Summer, 2019, internet searches were conducted to locate, obtain, and review readily available documentation related to and focused on in-situ sediment remediation projects - conducted anywhere, any time - that specifically involved fiber sediments.

Understandably, workers in different countries (researchers, consultants, authorities, etc.) often use a wide variety of names and terminologies when referring to what we in Sweden call ”fiber sediments”; d.v.s. there is no international consistency. Therefore, multiple searches were required using different combinations of key words or phrases, including, t.ex. ”fiberbanks”, ”fiberbank deposits”, ”deposits”, ”pulp mills”, ”paper mills”, ”wood pulp”, ”waste discharge”, ”fibrous sediment”, ”fiber-rich sediment” ”organic-rich sediment”, ”organic-enriched sediment”, ”cellulose-rich sediment”, specific country names, etc. To underscore: Despite the relatively extensive nature of the internet searches conducted, we do not claim that the information presented in this section is exhaustive and complete.

As expected, search results indicated that the fiber-sediment sites for which information was available are at different stages of progress towards the end-goal of remedy implementation using in-situ and/or ex-situ methods. Thus, when summarizing results, a distinction was made, when possible and practical, between:

  • Sites that are potential, suspected, or clearly identified as fiber-sediment sites, versus
  • Sites that have also been investigated, at least to some degree, versus
  • Sites at which in-situ and/or ex-situ remedies have also at least been considered, versus
  • Sites at which in-situ (and/or ex-situ) remedies have apparently been implemented.

For sites at which in-situ remedies have been considered if not also implemented, no judgements are made herein as to whether we agree, or not, with the site-specific remedial decisions. Furthermore, the specific names or acronyms used for in-situ remedies as reported in the referenced documentation (t.ex. MNR, natural recovery, EMNR) are used herein, but are instead ”translated” into remedy terminology consistent with that provided in Section X, Table 1.

If and when an ex-situ (dredging) remedy has been considered for or implemented at a particular international site, such is also noted herein – particularly in cases where one or more in-situ remedies were also considered. In so doing, at least some level of insight is gained into the decision-making processes that have occurred for particular international sites.    

Additionally, in reviewing and summarizing documentation, attention was also paid to references made to other ”items of interest”, t.ex. observations of high gas content and/or pockmarks, speculation on sediment responses to capping, authority perspectives on remedial methods, etc.

In-situ remediation projects in Sweden

Based on reports published by SGU, the number of sites (or areas) in Sweden at different stages of progress towards the end-goal of remedy implementation are as follows:

  • Sites/areas with potential for past or current fiber waste-generating activities – ca. 380.
  • Sites/areas that have been investigated, at least to some degree - 41.
  • Sites/areas at which in-situ and/or ex-situ remedies have at least been considered – unknown.
  • Sites/areas where in-situ remedies have been implemented – 2 (see below).

Completed projects

To-date, a total of three in-situ capping projects have been completed at two Swedish fiber-sediment sites. Two of the projects can be considered as conventional isolation capping and the third considered as FÖNS (see Section X, Table 1). Apparently, no other type(s) of in-situ remediation projects (ÖNS, active isolation capping, or AC-based thin-layer capping) have been conducted yet at fiber-sediment sites in Sweden. 

The following table is taken from Jersak et al., 2016 c and modified to list only projects occurring at fiber-sediment sites. Note, project-specific references in the table are provided in Jersak et al., 2016 d.

Site or project name

Where

When

General descriptions of site, project, and cap design

References

Lake Turiningen

Södermanland

1999 -2000

- Fiber-rich lake sediments near stream mouth contaminated by Hg.

- Cap design: Basal geotextile overlain by ~ 20 cm fine-grained sand (in some areas, ~ 20-40 cm of crushed rock for erosion protection, in addition to or instead of sand layer).

- Capping area: approx. ~ 40,000 m2.

Bergman, 2012; Nykvarns kommun, 2004

2001-02

- Soft, fiber-rich sediments in deeper parts of lake also contaminated with Hg.

- Cap design: several cm of an “artificial” (aluminum-based) sediment material, derived from a placed “gel” material.

- Capping area, ~ 800,000 m2.

Naturvårdsverket, 2003; Petsonk and Bergman, 2006

Tollare

Stockholm

2008

- Fiber sediments in lake contaminated by Hg.

- Cap design: Basal (and weighted) geotextile overlain by a layer of crushed stone for erosion protection. Thickness of crushed-stone layer unclear.

See Jersak et al., 2016 b for references.

 

Some information (although somewhat dated) is readily available on installation, effectiveness, and/or performance of the three Swedish capping projects listed above. Available information can be briefly summarized as follows:

Lake Turingen.

  • From Nykvarns kommun, 2004 (see Jersak et al., 2016 d for reference).
    • For the cap consisting of geotextile plus a crushed-rock layer: “Arbetet gick i stort sett planenligt och kunde genomföras utan ytterligare spridning av kvicksilver. Cirka 95 % av det tillgängliga kvicksilvret isolerades. Mätningar visar att kvicksilverhalten i nybildat sediment i sjön minskade avsevärt efter dessa åtgärder.”
    • For the thin, artificial cap: “Önskad tjocklek på täckningen har i huvudsak nåtts. På flera ställen i sjöns djupare delar har dock det konstgjorda sedimentet blandats med de naturliga sedimenten. Orsaken verkar vara den gasbildning som tidvis förekommer i dessa bottnar.” Okså, ”Mätningar av halten totalkvicksilver i vattnet nära sjöbottnen visar en tydlig minskning som sannolikt är ett resultat av det konstgjorda sedimentet.”
  • From Envipro, 2009.
    • For the thin, artificial cap: “De uppföljningar som hitills gjorts i Turingen visar att täckningen sannolikt är känslig för gasbildning i underliggande sediment (om sådan förekommer) varvid omblandning av förorenade sediment och täckningsmaterial kan ske.”
  • From Hifab, 2011.
    • For the cap consisting of geotextile plus a crushed-rock layer, “Kontroller och uppföljningar visade att nedsjunkningar uppkom antingen i samband med att täckningen etablerades, eller kort tid därefter. En alternativ förklaring är att gasutveckling i sedimenten skapat upptryckningar som lett till att täckningsmassorna förflyttats och geotextilen ”bubblat upp.”
  • From Bergman, 2012 (see Jersak et al., 2016 d for reference).
    • For the thin, artificial cap: The author poses the question why are Hg levels in biota decreasing slower than levels in the water, but does not appear to directly answer the question.
  • From Edebalk, 2013, “Goda erfarenheter av ny teknik. Den övergripande målsättningen om isolering av åtminstone 90 % av Hg-förrådet har uppfyllts. Det är för tidigt att dra slutsatser om långsiktiga delmål.”
    • Note: It is unclear if the author is referring to one or both of the projects.

Tollare.

From Hifab, 2011, “I projekt Tollare användes en mer avancerad typ av armering [jämfort med Turingen] som lades ut och sedan täcktes med tunna lager av erosionsbeständigt krossmaterial. Med hänsyn till risken för att gas i sedimenten skulle kunna orsaka upptryckning användes en genomsläpplig geotextil i armeringen och likaså genomträngliga massor i täckningen.”

turingen cap place NV

Figur 1. Placement of thin-layer (konstgjört) cap, Lake Turingen, Sweden (source: Naturvårdsverket).

Tollare Byggvarlden

Figur 2. Cap design, Tollare, Sweden (source: Byggvärlden).

 

tollare 2

Figur 3. Cap construction (duk placement), Tollare, Sweden (source: Byggvärlden).

 

In-situ remediation projects in other countries

Information related to remedies considered, selected, or implemented at specific fiber-sediment sites/areas was found for three additional countries, namely: Canada, Finland, and the USA.

Canada

A total of five fiber-sediment sites/areas have been identified and investigated to different degrees, including: Cornwall, Boat Harbour, Thunder Bay, Jackfish Bay, and Howe Sound (Chapman, 2018; Government of Nova Scotia, 2018; Nova Scotia Lands Inc., 2018; Environment Canada, 2014; Alava, 2016; additional references below).

As summarized below, in-situ and/or ex-situ (dredging) remedies were considered, selected, or implemented for each of the five sites/areas. The year for which the most recent documentation was available is indicated. Note, for Howe Sound, details were unclear:

  • Cornwall - Natural recovery (ÖNS) was selected (as of 2018).
  • Boat Harbour – Dredging was selected (as of 2018).
  • Thunder Bay – Dredging was selected (as of 2019).
  • Jackfish Bay - Natural recovery (ÖNS) was implemented (as of 2014).
  • Howe Sound - Natural recovery (ÖNS) was apparently selected (date unclear).

fiberbanksed envir canada

Figur 4. Fiberbank sediment, Thunder Bay, Canada (source: Environment Canada).

Additional items of interest noted in documentation for two of the sites/areas, Cornwall and Thunder Bay, include the following:

  • Cornwall (Biberhofer and Rukavina, 2002; Razavi et al., 2013; Fathi et al., 2013; Environment Canada, no date):
    • Sediments were recognized as ”gas-enriched”, with significant ebullition observed.
    • Noted a general correlation between high fiber content and high gas release, including when sediments were physically disturbed.
    • Authorities state no significant environmental benefit would be expected from dredging or capping.
    • ”Neutrally-buoyant wood liter” (2-3 cm) was observed in site areas with high gas content.
    • Pockmarks were apparently observed, based on the following quote (in Biberhofer and Rukavina, 2002): ”[it is] evident from underwater video that the sediment-water interface was disturbed or dimpled due to the collapsing of gas pockets when gas escaped from the sediment”.
  • Thunder Bay (Environment Canada, 2018; Franz, 2013; Cole, 2015):
    • In-situ remedies (natural recovery, some type of capping) were considered. However, dredging was determined to be the best remedy.
    • Reference was made to sediment gas, and to ”fibrous sediment” specifically.
    • In evaluating a capping option, one consultant (Cole, 2015) noted:
      • Gas in the ”enriched organic sediment (EOS)” could penetrate the cap material, with likely release to the overlying water column.
      • A cap load could cause ebullition and enhanced transport of porewater and gas-borne contaminants.

Finland

A total of four fiber-sediment sites/areas have been identified, including: Kymijoki River, Lake Vatianjärvi, Lake Saimaa, and the Äänekoski watercourse (Verta et al., 2009; Ratia, 2013; Ratia et al., 2014; Pöykiö et al., 2008; Committee for the Gulf of Bothnia, 1987; Elinkeino, 2011).

Note, it is unclear if the Äänekoski watercourse actually includes one or more of the other sites/areas. Also note Kymijoki River appears to consist of multiple sites.

Investigations, including biological assessments, have apparently been conducted by Finnish academics at several of the sites/areas. However, the only site/area for which remediation-related discussions have occurred was Kymijoki River (Verta et al., 2009; Elinkeino, 2011). For this site/area:

  • Different remedial methods have been examined, mainly dredging and capping.
  • Dredging was/is apparently considered best, from a cost point-of-view.
  • General reference is made to an in-situ pilot capping project. However, details are unclear.

USA

Interestingly, in the USA - where the greatest number by-far of in-situ (and ex-situ) sediment remediation projects have been conducted to-date, worldwide (Jersak et al., 2016 c) - there appear to be relatively very few fiber-sediment sites identified and investigated, much less remediated.

A total of five fiber-sediment sites/areas have been identified, including: Ward Cove, Former Scott Paper Mill, Boise St. Helens Pulp/Paper Mill, Port Angeles Harbor, and Whatcom/Bellingham Bay (Herzog, 2012; Integral, 2009; Wash. State DOE, 2012; Oregon DEQ, 2016; Magar et al., 2009).

For many of the sites/areas, different types and levels of investigations have been conducted, and remedies have at least been considered. However, remedies have been implemented at only two of the sites/areas to-date, namely:

  • Former Scott Paper Mill – Dredging was implemented, apparently during 2011 (Herzog, 2012).
  • Ketchikan Pulp Company (Ward Cove) – A combination of MNR (ÖNS), EMNR (FÖNS), and dredging was implemented during 2000 (Integral, 2009).

 

References

Alava, J. 2016. Dioxin and furan contamination from pulp mills: A successful history of source control and regulations. Whats happening with dioxin and furan contamination in Howe Sound? Ocean Watch, Howe Sound Edition. Available at:

oceanwatch.ca/howesound/wp-content/uploads/sites/2/2016/12/OceanWatch-HoweSoundReport-PulpMill-1.pdf.

Biberhofer, J. and N. Rukavina. 2002. Data on the distribution and stability of St. Lawrence River sediments at Cornwall, Ontario. NWRI Contribution: 02-195. July 2002.

Chapman, P. 2018. Sediment remediation can include no action. Ecotoxicol. Environ. Contam. Vol. 13, No. 2, pp. 1-3.

Cole Engineering Group Ltd. (Cole). 2015. Thunder Bay North Harbour, City of Thunder Bay. Sediment management options evaluation, revised final report. WR13-0704. March 2015.  

Committee for the Gulf of Bothnia. 1987. Water pollution problems of pulp and paper industries in Sweden and Finland. No. 28. May 1987.

Edebalk, P. 2013. Erfarenheter från efterbehandling av förorenad mark. Ett urval av projekt som genomförts med statliga medel 1999-2007. SGI Publikatoin 3, 2013.

Elinkeino-, liikenne- ja ympäristökeskus (Elinkeino). 2011. Remediation of the contaminated sediments in the river Kymijoki between Kuusansaari and Keltti, Environmental assessment impact procedure. Available at: https://www.ymparisto.fi/download/noname/%7BB7FB5F4A-90B0-4B54-8327-B68D3FAC2308%7D/116446.

Envipro/Hifab. 2009. Luleå kommun. Huvudstudie Karlshäll. 2007:01 Riskvärdering. Luleå kommun. SLUTRAPPORT. 2009-03-04.

Environment Canada. No date. Cornwall sediment strategy. Available at: https://www.rrca.on.ca/_files/file/brochure-Cornwall-Sediment-Strategy.pdf?phpMyAdmin=415bcc74a9c69072ce5800d6de86a905.

Environment Canada. 2014. Jackfish Bay Area of Concern in Recovery. Newsletter 2014. Available at: http://publications.gc.ca/collections/collection_2014/ec/En164-33-1-2014-eng.pdf.

Environment Canada. 2018. Thunder Bay North Harbour, Contaminated Sediment Management. October 2018. Presentation available at: https://www.documentcloud.org/documents/5637208-TBNH-SMO-Update-Presentation-ECCC-Oct-29-2018.html.

Fathi, M., J. Ridal, D. Lean, and J. Blais. 2013. Do wood fibers from a pulp mill affect the distribution of total and methyl mercury in river sediments? J. Great Lakes Res. Vol. 39, pp. 66-73.

Franz Environmental Inc. (Franz). 2013. Thunder Bay North Harbour, site specific risk assessment with sediment management strategy and NCSCS classification. Final report. June 21, 2013.

Government of Nova Scotia. 2018. Boat Harbour Remediation Project. December 2018 Update. Available at: https://novascotia.ca/boatharbour/documents/boatharbour-project-planning-and-progress-12-2018.pdf.

Herzog, J. 2012. Former Scott Paper Mill site remediation and restoration. Terra et Aqua. No. 128, pp. 9-14. September 2012.

Hifab. 2011. Kompletterande huvudstudie av förorenade sediment i Viskan. Rapport VISKAN 2009:07. Sammanfattande resultatredovisning, riskbedömning och åtgärdsutredning. 2011-06-30.

Integral Consulting Inc. (Integral). 2009. Final remedial action report. Sediment remediation in Ward Cove, Marine Operable Unit, Ketchikan Pulp Company site, Ketchikan, Alaska. September 30, 2009.

Jersak et al. 2016 c. In-situ capping of contaminated sediments. Remedial sediment capping projects, worldwide: A preliminary overview. SGI Publication 30-4E (in English). www.swedgeo.se.

Jersak et al. 2016 d. In-situ capping of contaminated sediments. An extensive up-to-date collection of relevant technical and other international references. SGI Publication 30-6E. www.swedgeo.se.

Meriläinen, P. 2007. Exposure assessment of animals to sediments contaminated by pulp and paper mills. Academic dissertation. University of Jyväskylä.

Novia Scotia Lands Inc. 2018. Project Description, Boat Harbour Remediation, Planning and design, Pictou Landing, Nova Scotia. December 18, 2018. Available at: https://ceaa-acee.gc.ca/050/documents/p80164/126476E.pdf.

Magar, V., Chadwick, B., T. Bridges, P. Fuchsman, J. Conder, T. Dekker, J. Stevens, K. Gustavson and M. Mills. 2009. Technical Guide – Monitored Natural Recovery at Contaminated Sediment Sites. ESTCP Project ER-0622. May 2009.

Pöykiö, R., H. Nurmesniemi, and V. Kivilinna. 2008. EOX concentrations in sediment in the part of the Bothnian Bay affected by effluents from the pulp and paper mills at Kemi, Northern Finland. Environ. Monit. Assess. Vol. 139, pp. 183-194.

Ratia, H. 2013. Ecotoxicological status of a watercourse recovering from heavy loading by pulp and paper industry. Academic dissertation. University of Jyväskylä.

Ratia, H., E. Vehniäinen, A. Rusanen, and A. Oikari. 2014. Recovery of historically contaminated watercourse polluted by the chemical wood industry: EROD activity in fish as biomarker. Soil Sed. Contam. Vol. 23, pp. 211-225. 

Razavi, N., J. Ridal, W. De Wit, M. Brian, C. Hickey, L. Campbell, and P. Hodson. 2013. Ebullition rates and mercury concentrations in St. Lawrence River sediments and a benthic invertebrate. Environ. Toxicol. Chem. Vol. 32, No. 4, pp. 857-865.

State of Oregon Department of Environmental Quality (Oregon DEQ). 2016. Boise St. Helens Pulp and Paper Mill Cleanup Site (ECSI 14). Fact Sheet. November 2016.

Verta, M., H. Kiviranta, S. Salo, O. Malve, M. Korhonen, P. Verkasalo, P. Ruokojärvi, E. Rossi, A. Hanski, K. Päätalo, and T. Vartiainen. 2009. A decision framework for possible remediation of contaminated sediments in the River Kymijoki, Finland. Environ. Sci. Pollut. Res. Vol. 16, pp. 95.

Washington State Department of Ecology (Wash. State DOE). 2012. Port Angeles Harbor, Sediment Characterization Study, Port Angeles, Washington. Sediment investigation report. December 2012.’’&*