All entities that, as a result of a certain activity, need to discharge industrial wastewater and/or water subject to Regional Regulation No. 4/2006 (rainwater and washing of outdoor areas) into the sewer system must obtain a Discharge Authorization issued by the competent authority.
For Have more specific technical information
and in reference to the tariff for industrial discharges
Of industrial utilities contact:
The different authorization processes can be traced to the case histories as described below with their respective normative references:
The AUA measure has aDuration of 15 years, calculated from notification by the S.U.A.P..
Regarding AUA proceedings all information is available on the website of theProvince of Como, referred to for any specific details about procedures and forms. Click here to locate the SUAP of reference.
Regarding AIA proceedings all information is available on the website of theProvince of Como, referred to for any specific details about procedures and forms.
The permit/renewal/substantial amendment application for industrial wastewater and/or first rain water discharges to sewer must be submitted jointly with the waste management application. The discharge permit flows into the authorization measure for the operation of waste recovery and disposal activities, which has aduration of 10 years, calculated from the notification of the measure.
Regarding the proceedings of AUT.UNICA ex art.208 all information is available on the website of theProvince of Como, to which we refer for any specific details aboutprocedures and forms.
The application must be submitted telematically via PEC directly to the Area Office, to whose website, in the forms section, please refer for any specific details www.ato.como.it.
The authorization has a duration of 4 yearscalculated from the notification of the measure.
One year before its expiration, its renewal must be applied for in accordance with Art. 124 paragraph 8 of Legislative Decree 152/06.
The fees for the collection and purification service of production wastewater discharged into public sewers are determined in compliance with the provisions on tariff determinations made by the Como Province Ambit Office by resolution of November 20, 2018 in application of ARERA Resolution 665/2017/R/idr of September 28, 2017.
Specifically, the fees for collection and treatment service for industrial users are broken down according to the following general structure:
In summary, the calculation of how much is due is related to the sum of afixed fee (QF), acapacity share (QC)quantified by the maximum volumes and concentrations of COD and suspended solids (SST) allowed at the discharge and avariable quota (QV)related to the actual quality of effluent and volumes discharged.
1. The FIXED QUOTE (QF).
The fixed fee was calculated by applying the limit of 5% of the total revenue for industrial wastewater collection and treatment service as stipulated in Section 16.5 of the TICSI.
Article 16 of Annex A provides for the quantification of the fixed fee based on the following three costs:
- User contract management;
- Costs of measuring discharged volumes;
- Costs of industrial effluent quality audits.
The components related to (a), (b) and (c) were defined by considering five cost items below:
- personnel costs;
- LAB costs;
- maintenance costs;
- transportation costs;
- administrative costs.
In summary, the following costs can be identified:
- User contract management;
- Costs of measuring discharged volumes;
- Costs of industrial effluent quality audits.
Costs under b and c also include fixed items related to direct costs, which companies incur for the maintenance of samplers, meters and remote monitoring, which will be directly charged to the companies where these systems are installed. Specifically, these costs are:
- SAMPLER COST;
- Meter cost;
- cost per telecontrol.
In this way each user will have his or her fixed fee defined by the sum between:
- Contract management cost (administrative costs);
- measurement costs (if meter and/or sampler present allocated in maintenance costs);
- Costs of industrial effluent quality testing (personnel cost + laboratory cost + maintenance cost + transportation cost, commensurate with annual volumes discharged).
2. The CAPACITY QUOTA (QC).
It is quantified based on the maximum COD and Suspended Solids concentrations stipulated in the permit documents and the maximum authorized volume for the discharge with application of the following formula:
Where:
- %COD, aut and %SST, aut are the percentages that, when applied to the unit capacity tariff TdcapacityATO, represent the cost share allocated to COD and SST pollutants (%) and take the same values as established for %COD and %SST;
- COD aut,p and SSTaut,p are the concentrations found in the permit documents (mg/l);
- Vaut,p is the maximum volume authorized for discharge;
- The Sqc coefficient, a threshold placed on the incidence of the capacity share to the total revenue for wastewater collection and treatment service was set equal to 5%;
- Td capacity
3. The VARIABLE QUOTA (QV).
VARIABLE QUOTA - QVpATO THE UNITARY SEWAGE TARIFF.
The Area Governing Body resolves the sewerage unit tariff, expressed in €/mc.
The Area Governing Body, or other competent entity may introduce a multiplicative factor α to account for effluents of a specific nature that result in an impact on sewer infrastructure costs due to their corrosive or encrusting characteristics.
α was set equal to 1.
VARIABLE QUOTA - QVpATO THE UNITARY DEPURATION RATE.
The Area Governing Body resolves the unit purification tariff, expressed in €/mc.
The percentages that, when applied to the unit rate, determine the abatement costs of the main pollutants COD, SST, N, P assume, as a rule, the “standard” values shown in the table below. The standard values also include ranges.
Based on the industrial fabric present in the Como area and the existing sewage treatment plants, the EGA considered it appropriate to consider parameter values different from the standard ones, but within the ranges, in order to better represent the cost of the different treatments, especially COD, in terms of energy costs, disposal and removal of its refractory share. This also makes it possible to optimize the distribution of the cost percentages of some parameters (SST and N), while keeping the percentage of phosphorus removal (equal to 5%) unchanged.
Changes in the percentages to be applied to the various parameters are shown below:
- %COD 52 to 57
- %SST 28 to 25
- %N 15 to 13
VARIABLE QUOTA - QVpATO THE UNITARY DEPURATION RATE - additional parameters.
Among the parameters to be considered for the calculation of the variable quota, the formula allows for the identification of additional parameters with respect to COD, SST, N, and P under the condition of the existence in the reference ATO, of at least one treatment plant with specific stages for the removal of the parameter in question.
In this regard, and as a parameter “Xj,p” the “Color” as a parameter characteristic of the textile industry present in the area.
An additional J-th parameter identified as BOD5 is introduced, to be included in the formula with a negative coefficient of “-7” and to be applied to those users who have discharge limits greater than 40 mg/l (reference limit).
This modification also makes it possible to modulate the cost of treating BOD according to its biodegradability. In fact, the introduction of this parameter makes it possible to better satisfy the principle of “polluter pays,” as the input of BOD5 through the discharged effluent facilitates all pre-denitrification processes that perform better in the presence of readily biodegradable carbon, while limiting the purchase of external carbon sources.
Expenditure constraint for each user
Pursuant to the provisions of ARERA Resolution 655/2017/R/idr, the annual expenditure of each production user for the same effluent discharged (volume and qualitative characteristics) cannot be increased by more than 10% per year compared to the expenditure incurred under the former method.
Below are the rates in effect as of 01.01.2026:
In order to verify compliance with the limits of acceptability of the wastewater discharged and identify the concentrations of the main and specific pollutants to be used for the determination of the fee for sewerage and purification services, the Manager shall draw up an analysis plan ensuring on each user the minimum annual number of analytical determinations required.
Analytical determinations are made according to relevant procedures and regulations.
The customer has the right to be present at all stages of control, including sampling, opening of the sample, and performance of the analysis. The operator is obliged to deliver to the user who requests it, a portion of the sample taken by the user, in order to ensure that the customer can perform the analysis at a laboratory of his or her choice, without prejudice to the operator's ability to be present at the stages of opening the sample and performing the analysis from the customer.
The concentrations of the main and specific pollutants used in the tariff formula are determined as an arithmetic average of the values obtained during the year, weighted over the period volumes in order to ensure maximum representativeness of the final quality determined and compliance with the “Polluter Pays” principle.
For the purpose of determining the charge for sewerage and purification services, the determination of the discharged volume is done, as a rule, by assuming the discharged volume equal to the volume of water withdrawn from the waterworks.
In the presence of private drawing points or as a result of production processes that decrease or increase the quantities of effluent discharged compared to the water withdrawn, the determination of volume is made by suitable measurement performed at the point of discharge, with meter installation.
Drains without a meter will be progressively equipped with a meter at the discharge, according to the Regulations.
However, the user may at any time request the installation of the measuring instrument at the discharge point.
The operator reserves the right to assess the technical feasibility of installing the meter and granting the request, as well as to identify the type of meter to be installed for each specific case in relation to the conditions and characteristics of the individual discharge.
Costs for the purchase and installation of metering instruments are borne by the discharge holder - recovered by the Manager through an increase in the fixed fee of the tariff.
In the meantime, the determination of discharged volumes will be made by the operator by assuming the discharged volume to be equal to the volume of water withdrawn from the aqueduct, or by reasonable and reasoned estimate based on a technical report submitted, by January 31 of each year by the discharge holder and accompanied by the following documentation:
- MUD and/or copies of disposal forms;
- Accurate water balance that provides:
- readings of internal meters (readings, consumption and photos of meters to be attached) if installed;
- calculation of the shares dispersed in the product based on “recipes” and production in the reference period;
- Technical specifications of machines and equipment that generate a water leakage (reports and specifications provided by the manufacturer).
Lump sum, estimated, and percentage deductions will not be considered.
In case of unavailability of the volumes discharged and taken from private sources, the volume is set equal to the maximum value between the volume authorized for discharge and the volume recorded in the last billing.
AUTONOMOUS SOURCES OF SUPPLY
All those who obtain their water supply in whole or in part from sources other than the public aqueduct network are required, at their own care and expense, to install and properly maintain suitable instruments for measuring the quantity of water withdrawn.
Measuring instruments must comply with current regulations and be prepared for remote reading, as well as be placed immediately downstream of the intake point before any possible shunts.
The operator reserves the right to take periodic meter readings and to install meters equipped with remote reading in order to capture readings and monitor consumption.
IDA Carimate
At the Carimate sewage treatment plant, recovery (R12 and R13) and disposal (D8) operations of non-hazardous liquid waste are carried out. Fees, EWC codes and methods of accessing the service are indicated in the Regulations.
Document links:
- AIA Carimate No. 317/2019
- Waste Regulations
- Waste sheet
- RENTRI data
- Facsimile fir D8
- Facsimile fir R12
- Facsimile fir R13
For information, you can contact 031-7897902 (Eng. Giorgio Citterio and Eng. Barbara Frigerio) or send an e-mail to dep.carimate@comoacqua.it
IDA Mariano Comense
At the Mariano Comense sewage treatment plant, disposal operations (D8) of non-hazardous liquid waste are carried out. Wastewater withdrawal for reuse for industrial purposes is also possible. The Regulations indicate the fees, CER codes and how to access the service.
Document links:
- Waste and Reuse Regulation 2025
- Authorization for the treatment of non-hazardous liquid waste - Legislative Decree 152/2006 and ss.mm.ii. art. 110 c.3
- RENTRI data
- Facsimile firD8
For information you can contact 031-752064 (Eng. Barbara Frigerio and p.i. Jasmine Scabbio) or send an email to dep.mariano@comoacqua.it