Implementation of the UWWTD in relation to the WFD SDEAs input - - PowerPoint PPT Presentation

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03/03/2020, Brussels/Bruxelles

Implementation of the UWWTD in relation to the WFD

SDEA’s input

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Implementation of water directives in France

• Implementation of UWWTD through french water laws (« Loi sur

l’eau ») – 1992, 2006 and regulations (1994, 2007, 2015)  National effort towards WWTP and networks (all sizes from 20 EP)  Rainfall admission limitations  2nd wave : raintime works (2007, enforced in 2015)

• WFD : coordination through water policies and agencies, but more

difficulties to find stakeholders responsible for quality status

Results : progressive wastewater management & river status improvement Some coordination and uncertainties remain for some cases (timing, costing, …)

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WWTP 2000 PE WWTP 25 000 PE

1st source of uncertainty: notion of « Agglomeration » (French/English)

Agglomération (french sense) : large urbanization group WWTP 1 000 000 PE 1, 2 or 3 UWWTD agglomerations? If 1 : should the 2000-PE WWTP apply the 1 000 000-PE WWTP regulations? Should all 3 use the same treatment standard (ex. N, P) if the smallest WWTP is the only one in an eutrophication-sensitive area?

?

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2nd source of uncertainty: notion of « costs »

Art 3 : excessive costs UWWTD Art 4 : disproportionate costs WFD

Different wordings = different studies for the same project? France considers those 2 notions as totally different : could it be a better coordination with similar terms? Are costs exceding only a part

• f a resolution excessive?

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3rd source of uncertainty: prioritisation of approaches

UWWTD

MEANS objectives (treat all/most wastewaters, with few reference to receiving waters)



WFD

RESULTS objectives (good status)

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Rainwater effects on unitary devices (1/2)

Unitary devices = takes both waste waters and urban rainfall waters Deemed appropriate within the 3 first quarters of 20th century – treatment of weak rainfall flows and first / most polluted flow Storm discharges in case of heavy (or, in some cases, moderate) rain (direct discharge of diluted waste water)

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UWWTD, annex 1 :

Rainwater effects on unitary devices (2/3) – discharge limitation

Definition far less precise than those in DWD : Which number may be deemed « acceptable »? 20? 30? What is an acceptable dilution rate? 5% ? 10%? Risk of uneven or inequitable application in member states. Precision? Benchmark? Inacceptable discharge according to local or MS regulations No reference to WFD results Insufficient WFD/UWWTD coordination risk : Work to do, but will it be the most efficient one?

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Rainwater effects on unitary devices (3/3) – directives coordination / exemple

Overflow 2 : unacceptable discharge in good-status river Overflow 1 : acceptable discharge in bad-status river Works to lessen overflow 2’s impact may :

• Report some of the overflow

to overflow 1, thus worsening the status of the most polluted river

• Simply consume most

credits available for a less- efficient project

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Thanks for listening!