Data gathering and impact assessment for a possible technical review

of the IPPC Directive – Part 2

Factsheet B.4. Independently operated wastewater treatment plants

Potential amendment B 4: Addition of independently operated industrial wastewater treatment plants which serve one or more other activities of annex I

Status: final– 12/09/2007

1.Issue

Aim of the study: The present work identifies the issues related to the addition to the Annex I activities of independently operated industrial wastewater treatment plants which serve one or more other activities of Annex I. The current work is based on a background literature survey, a meeting with DG ENV, and inputs from various MemberStates, and other stakeholders. It also takes into account the comments of the Advisory Group members on the draft final report
Background:
Activities concerning waste management covered under the IPPC Directive are listed in Annex I Section 5 of the IPPC Directive. Nevertheless, given the current activities definitions specified in this section, it is not clear whether waste water treatment plants in general, and industrial waste water treatment plants in particular, are under the scope of IPPC. During a discussion on activities 5.1 and 5.3 in ameeting of the “IPPC expert’s sub group on interpretation of Annex I and ‘installation’” in July 2005, the issuewas raised that most MS had not considered the application of these activities to WWTPs. Several MS pointed out that, even if WWTPs were not themselves covered when operated as dedicated stand-alone facilities, they would be covered as part of an installation when on the same site and technically connected to an Annex I activity, such as a tannery. Other MS interpret that the operator of the Annex I activity and non-Annex I activity should be the same in order to comply with the definition of installation covered under the IPPC Directive (article 2 of the Directive). According to the guidance on the interpretation of "Installation" and "Operator" for the Purposes of the IPPC Directive published by the European Commission, the independence of this type of installations is not determined by the ownership/operation. Therefore, an industrial waste water treatment plant that is technically connected with the activities ofan Annex I activitycarried out on the site will be covered by the IPPC Directive even if it has a different operator.
Issue summary:
An assessment was made of the extent to which independently operated waste water treatment plants are already covered under the IPPC Directive, either by virtue of inclusion in broader “installations” (i.e. the wastewater treatment plant is already part of an installation containing another Annex I activity), or because of the interpretation of the Annex I Section 5 activity descriptions.
An important issue to be covered in this analysis wasthe estimation of the number of such plants in Europe, and the nature of their "independence". For example, a plant may be considered to be independently operated because it has a different operator than the connected Annex I activity, despite being technically in the same installation, or is it considered independent for some other reason (e.g. not being on the same site or it also serves unrelated non-Annex I activities)?
Consequently, the following issueswere covered:
-Are all or most of these WWTPs already covered under the IPPCDirective because they can be seen as directly associated activities which are technically connected to an Annex I activity?
-To what extent are they already covered under the IPPCDirective anyway because they fall under Annex I Section 5.1 and 5.3 activities?
-If added, what threshold should be assigned?

2.Current practice

2.1. Scope of the sector

Background information on waste water treatment (e.g definitions, processes, etc) can be found in Annex A.

a.Characterisation of industrial waste water

Industrial waste waters are originated during the myriad of industrial processes that utilise water for a variety of purposes. In addition to the large quantities used for cooling purposes, water is extensively used through industry process operations. This water is usually altered considerably after been used in the industrial process and may contain contaminants that degrade the water quality such as nutrients, suspended sediments, bacteria, oxygen-demanding mater, and in some cases toxic substances [Corbitt, 1998].

A flow diagram for a hypothetical plant complex, illustrating water flows and some of the most typical treatment processes that might be used are presented in figure 1.

1

VITO and BIO, with Institute for European Environmental Policy and IVM

Data gathering and impact assessment for a possible technical review

of the IPPC Directive – Part 2

Factsheet B.4. Independently operated wastewater treatment plants

Figure 1: Water use flow diagram for a hypothetical industrial plant

Source: [Based on Corbitt, 1998].

1

VITO and BIO, with Institute for European Environmental Policy and IVM

Data gathering and impact assessment for a possible technical review

of the IPPC Directive – Part 2

Factsheet B.4. Independently operated wastewater treatment plants

The quantity of water used by industry facilities vary widely, with some plants using up to 189,000 m3/day, while others use no more than comparable sized mercantile establishments. The composition of industrial effluents is equally as variable as flow rates and dependant on the type of industry [Corbitt, 1998]. In Annex B, a summary of the major water contaminants from some industrial sources are presented. Nevertheless, it is important to highlight that pollutant loading will vary within a given industry, and consequently, industrial wastewater characterisation must be done on a plant-by-plant basis. [Corbitt, 1998].Consequently, the involved processes for treating the water will vary depending on the type of industry and the components and characteristics of contaminants. In some cases, different industries with similar composition of the industrial effluents (e.g. meat production and dairy production installations) will share the same waste water treatment plant, as similar processing techniques will be required for the treatment of the water [EUREAU, 2007a].

The chemical, food, and pulp and paper industries are amongst the main industrial polluters of freshwater ecosystems.

Taking as an example the chemical industry, the main sources of waste water are [EC, 2003]:

  • chemical syntheses
  • waste gas treatment systems
  • conditioning of utility water
  • bleed from boiler feed water systems
  • blowdown from cooling cycles
  • backwashing of filters and ion exchangers
  • landfill leachates
  • rainwater from contaminated areas, etc.,

In the chemical sector, the amount of nitrogen and phosphorus emitted to water in 2004 was estimated to be 45,043 tonnes and 4,895 tonnes respectively. Regarding COD[1], the emissions to water were 332,493 tonnes in 2004. Considerable reductions have nevertheless been observed since 1999, 24% of COD emissions, and 22% and 47% for nitrogen and phosphorus respectively [Cefic, 2005].

b.Nature of the independence of this type of installations

There are several approaches to waste water treatment of industrial effluents, each of them having its advantages and disadvantages, depending on the situation:

  • decentralised waste water treatment facilities, treating the aqueous effluent at source and discharging into a receiving water (i.e. no central waste water treatment facility on site)-Not independently operated, associated activity that have a technical connection to one or more Annex I activities .
  • centralised waste water treatment, normally using a joint Waste Water Treatment Plant (WWTP)- There arecaseswhereIPPC industries join forces and operate together awaste water treatment plant.This happens in areas where there is a concentration of industries (i.e.steel industries or petrol installations).Waste water treatment varies andisspecific to the nature of waste water. They have a different operator that the activities of the Annex I they serve and they are not on the same site. Nevertheless, they have a technical connection with the Annex I activity they serve.
  • waste water discharge into a municipal WWTP– This type of waste water treatment plant often treats a mixture of domestic and industrial waste water.This plant is covered by the Urban waste water Directive (91/271/EEC), except if they treat only industrial waste water and discharge directly to the receiving water (see Article 11 of Directive 91/271/EEC)[2].
  • waste water discharge into a municipal WWTP with on-site pretreatment at source- Not independently operated, associated activity that have a technical connection to one or more Annex I activities carried out on the same site, and likely to have the same operator. Once the water is discharge into a municipal WWTP, the waste water is covered by the Urban waste water Directive (91/271/EEC), except if they treat only industrial waste water and discharge directly to the receiving water (see Article 11 of Directive 91/271/EEC)².

Decentralised waste water treatment has the advantage that facilities for treatment at source are tailor-made and thus normally show better performance. Furthermore, it allows avoidance of dilution by mixing of different waste water streams, normally resulting in higher treatment efficiency, and the cost benefit ratio can be much better in tributary stream treatment than in central treatment [EC 2003]. On the other hand, centralised or joint waste water treatment plants allows making use of mixing effects, such as temperature or pH adjustment, could allow a more effective use of chemicals (e.g. nutrients) and equipment, thus decreasing relative operating costs, and can, in individual cases, realise savings in capital and operating costs.

Therefore, some installations subjected to the IPPC-Directive have their own industrial wastewater treatment plants, while others (usually smaller) are directly linked to a central urban wastewater treatment plant as long as the composition of industrial effluents is similar to that of domestic waster waters.In such case, the industrial wastewater should meet the requirements as described in Annex I.C of the Directive 91/271/EEC on Urban Waste Water Treatment. Nevertheless, if these off-site plants treat only industrial water and discharge directly into the receiving water, they are not covered by the UWWT Directive (see Article 11).

As an example, European tanneries' waste water effluent is treated in many different ways. There aresituations in which an individual tannery applies waste water treatment steps on site. In other situations an individual tannery may apply (on site) only pre-treatment or a part pre-treatment or no treatment at all, sending the effluent to a communal or joint effluent treatment plant. These may be jointly owned and are usually dedicated to processing tannery effluent. A tannery might also treat its effluent partly on site, but then discharge to a municipal sewage works and make some financial arrangement for effectively sharing the role of effluent treatment [EC, 2003 b].

It is important to highlight that, from the Directive, a directly associated activity does not have to be on the same site but has to have a technical connection with the Annex I activities carried out on the site.

Industries connected to the sewage system and waste water treatmenthave clear responsibilities in enabling urban waste water treatment plants to cope with the requirement of the water framework directive (and future daughter directive on priority substances) and to preserve the potential of treated sludge for recovery and waste water for reuse. Urban waste water treatment plants are designed to remove certain pollutions (suspended solids, organic matters, nitrogen, and phosphorus) but not all. When an IPPC industry discharges waste water into urban sewerage network, it belongs to this industry to make sure that its discharges will not disturb the operations at the treatment plant or will not entail disproportionate treatment costs (including sludge treatment). In all cases, discharge consent should be signed up by IPPC industries and the owner of waste water work (usually municipalities). Article 11 of the Urban Waste Water Directive 91/270 empowerstheMemberStates toadopt specific regulations on the so-called "indirect discharge" [EUREAU, 2007]. Further, the article 2(6) of the IPPC Directive states that, with regard to indirect releases into water, emission limit values shall be applied at the point where the emission leaves the installation. The effect of a water treatment plant may be taken into account when determining the emission limit values of an installation, provided that the equivalent level is guaranteed for the protection of the environment as a whole and provided this does not lead to higher levels of pollution in the environment. All discharges from an IPPC industry must be regulated according to the IPPC principles, and consequently, the emission limits will be based on BAT and dilution is not a permissible solution.

As in many other countries, the general case in the chemical industry in France is that effluents are treated on-site[EC, 2003]. However, the use of municipal and joint industrial waste water treatment is sometimes encountered, e.g. in biochemical productions (such as vitamins or antibiotics via biochemical pathways), and for activities for which the flow rate and the load of the effluentremain manageable by a municipal treatment plant. In this case, a study of the impact ofindustrial streams on the municipal treatment plant (impact on operation and sludge disposal) is done and an “industrial release agreement” is signed between the plants and the local waste water management authority.

A Municipal Decree is issued that generally contains the following main provisions of theagreement:

  • pH of the effluent comprised between 5.5 and 8.5 (eventually 9.5)
  • temperature of the effluent <30°C
  • effluent not containing substances hazardous to the personnel of the municipal WWTP, the collecting network, the WWTP itself and its operation, the environment downstream of the WWTP and the further handling of the waste water sludge
  • either maximum flows and pollution loads to be discharged (BOD, COD, TSS, totalKjeldahl-N, (NO2+NO3)-N, non-biodegradable N, nitrification inhibitors, total P, othersubstances that might impact on the operation of the WWTP and the further handling ofsludge) or provisions concerning pretreatment / recovery installations to be operated by theindustrial site prior to discharge in the municipal sewer
  • financial conditions

The discharge convention further describes the technical conditions of the dischargeagreementfixed by the municipal decree [EC, 2003].

2.2. Size and structure of the sector

a.The sector in general

Several water and waste water associations and organisationsat the national and European level have been contacted to collect information on the amount and capacity of existing independently operated waste water treatment plants (see section 6). In most cases, it has been highlighted that due to the high variability of the composition of industrial effluents, most of the installations subject to the IPPC-Directive which require wastewater treatment apply end-off-pipe technologies treating the aqueous effluent at source [EC, 2007a; EC, 2007 b; EUREAU, 2007; Defra, 2007]. Therefore, the amount of independently operated waste water treatment plants,which are the focus of the current analysis, can be expected to be considerably smaller than on-site or decentralised waste water treatment facilities. Nevertheless, it has not been possible to gather figures to support the expected low number of this specific type of WWTP. None of the organisations that have been contacted have been able to provide with data on number and capacity.

In the case of the food, drink and milk production industry, most installations have an on-site WWTP, which either partially treats the waste water before it is sent off site for further treatment, or treats it for reuse on site or for direct discharge to the environment [EC, 2006 b]. Process waters generated in installations for the surface treatment of metal and plastic are also most often treated in on-site waste water treatment plants. The discharge is then usually sent to municipal (urban) waste water (sewage) treatment plants, or if the effluent is treated to a suitable standard, directly to surface waters [EC, 2006 c]. Similar approaches to waste water treatment of industrial effluents have also been reported in most of the BREFs.

In spite of contacts with relevant association and experts, information on the number of installations and on their capacity has thus not been identified. As it would be further discussed in section 2.5, the term “independently operated” have different interpretations in different countries, which makes more complex the determination of the number of independently operated waste water treatment plants, as the final figure will depend on this.

In the lack of relevant data for the determination of the size and structure of the sector, we will consider a particular type of waste water treatment installations, the so called physico-chemical treatment plants (Ph-c).

b.Physico-chemical treatment of waste water

As mentioned earlier, depending upon the composition of industrial waste water, a physico-chemical (Ph-c) treatment may be required. In the absence of more detailed information on the number of independently operated waste water treatment plants, we will focus our attention on this type of installations. Ph-c treatment plants are essential to medium and small companies, as they facilitate the correct disposal of waste water without causing much economic burden. Nevertheless, this type of installations representsafraction of the total number ofplants that treat industrial waters, as this type of plants do not include the biological treatment, which is sometimes required.

This type of installations ranges from blending systems with no actual chemical interactions to complex plants with a range of treatment options, some of them custom designed for treating specific waste streams.

The waste treated in Ph-c treatment plants is aqueous liquid. Ph-c plants generally treat waste liquids or sludges with a relatively high water content (>80 w/w-%). Regardless of their origin and their relationship to their material characteristics, the wastes commonly treated by these plants are:

  • emulsions/cooling lubricants
  • acids (e.g. picking acids from surface treatments)
  • alkaline solutions
  • concentrates/saline solutions containing metals
  • wash-water
  • waste water containing a gasoline/oil separator
  • solvent mixtures
  • sludges
  • aqueous liquid wastes with high concentrations of biodegradable materials
  • aqueous marine waste.

In Annex E, a table with the waste water types accepted in this type of plants in the United Kingdom can be found.