REPORT SNO. 7564-2020 The Norwegian river monitoring programme 2019 – water quality status and trends Photo: NIVA Photo: Norwegian Institute for Water Research REPORT Main Office NIVA Region South NIVA Region East NIVA Region West NIVA Denmark Gaustadalléen 21 Jon Lilletuns vei 3 Sandvikaveien 59 Thormøhlensgate 53 D Njalsgade 76, 4th floor NO-0349 Oslo, Norway NO-4879 Grimstad, Norway NO-2312 Ottestad, Norway NO-5006 Bergen Norway DK 2300 Copenhagen S, Denmark Phone (47) 22 18 51 00 Phone (47) 22 18 51 00 Phone (47) 22 18 51 00 Phone (47) 22 18 51 00 Phone (45) 39 17 97 33 Internet: www.niva.no Title Serial number Date The Norwegian river monitoring programme 2019 – water quality status 7564-2020 15th December 2020 and trends Elveovervåkningsprogrammet 2019 – vannkvalitetsstatus og -trender Author(s) Topic group Distribution Hans Fredrik Veiteberg Braaten, Cathrine Brecke Gundersen, Øyvind Environmental Open Kaste, James Sample, Dag Øystein Hjermann, Magnus Dahler Norling, monitoring Jose-Luis Guerrero Calidonio, Ian Allan, Luca Nizzetto Geographical area Pages Norway 87 + appendices Client(s) Client's reference Norwegian Environment Agency M-1817 | 2020 Client's publication: Printed NIVA Project number 16384 Summary In the Norwegian River Monitoring Programme (in Norwegian: Elveovervåkingsprogrammet) 20 rivers along the Norwegian coastline are monitored for chemical and hydrological parameters. It is a continuation of river monitoring with data from 1990. This report presents the current status (2019) and long-term (1990-2019) water quality trends. Four keywords Fire emneord 1. Rivers 1. Elver 2. Monitoring 2. Overvåking 3. Water quality 3. Vannkvalitet 4. Trends 4. Trender This report is quality assured in accordance with NIVA's quality system and approved by: Hans Fredrik Veiteberg Braaten François Clayer Sondre Meland Project Manager Quality Assurance Research Manager ISBN 978-82-577-7299-4 NIVA-report ISSN 1894-7948 © Norsk institutt for vannforskning/Norwegian Institute for Water Research & Norwegian Environment Agency. The publication can be cited freely if the source is stated. The Norwegian river monitoring programme 2019 – water quality status and trends NIVA 7564-2020 Preface The Norwegian river monitoring programme is a main component of the Norwegian water authorities’ surveillance monitoring in rivers, according to the requirements set by the EU Water Framework Directive (WFD). The monitoring also fulfils Norway’s obligations under the Oslo-Paris Convention (OSPAR). Since 2017, the Norwegian Institute for Water Research (NIVA), in collaboration with consortium partners, has carried out the monitoring activities. Results from the 2019 monitoring activities are presented in four thematic reports, where this report includes results from the basic monitoring of 20 rivers across Norway. The 20 rivers are selected to represent the variability in river water quality and fluxes, and to cover a substantial fraction of the riverine flux from mainland Norway to the sea. In 2019, the work presented in this report was a collaboration between NIVA, the Norwegian Water Resources and Energy Directorate (NVE), and Eurofins Environment Testing Norway AS. Hans Fredrik Veiteberg Braaten (NIVA) was project leader for the river monitoring programme in 2019, together with Cathrine Brecke Gundersen. Other co-workers at NIVA responsible for the results in the present report include Øyvind Kaste (catchment modelling, evaluation of sensor data), James Sample (databases, calculation of riverine loads, TEOTIL modelling), José-Luis Calidonio (catchment and TEOTIL modelling), Luca Nizzetto (catchment modelling), Ian Allan (catchment modelling), Rolf Høgberget (sensor monitoring), Dag Ø. Hjermann (climate and hydrology data), Liv Bente Skancke (coordination of local field work personnel, quality assurance of sampling and chemical analyses), Jan Karud (development of maps), and Elisabeth Lie and Marit Villø (contact persons at the NIVA chemical laboratory). Quality assurance of the report has been carried out by François Clayer. At NVE, Trine Fjeldstad has been responsible for the local sampling programmes, Stein Beldring has carried out the hydrological modelling, and Morten N. Due has been the administrative contact. In 2019, Eurofins carried out the total nitrogen and parts of the mercury analyses. Contact persons at The Norwegian Environment Agency have been Gunn Lise Haugestøl, Preben Danielsen and Eivind Farmen. Thanks to all involved for a good collaboration. Oslo, 30.11.2020 Hans Fredrik Veiteberg Braaten NIVA 7564-2020 Table of contents 1. Introduction ......................................................................................................................... 12 1.1 Monitoring objectives ..........................................................................................................12 1.2 Main rivers ...........................................................................................................................13 1.3 Additional Rivers .................................................................................................................15 2. Methods .............................................................................................................................. 17 2.1 Water discharge ...................................................................................................................17 2.2 Water temperature ..............................................................................................................17 2.2 Water quality sampling and analyses ..................................................................................18 2.2.1 Sampling methodology .........................................................................................18 2.2.2 Chemical parameters – detection limits and analytical methods ........................19 2.2.3 Quality assurance and direct on-line access to data ............................................20 2.2.4 Sampling and analyses for additional rivers .........................................................21 2.3 Calculation of riverine loads.................................................................................................21 2.4 Trend analyses and data comparison ..................................................................................22 2.4.1 Trend analysis methodology .................................................................................22 2.4.2 Selection of rivers .................................................................................................22 2.4.3 Selection of parameters and time-periods ...........................................................23 2.5 Comparison of metals data with EU WFD quality standards ...............................................24 2.6 Modelling of contaminants in the Alna river .......................................................................24 2.7 Sensor monitoring in Rivers Storelva and Målselva.............................................................27 3. Results and Discussions ........................................................................................................ 28 3.1 Climate and hydrology: status and trends ..........................................................................28 3.1.1 Air temperature and precipitation in 2019 ..........................................................28 3.1.2 Trends in air temperature and precipitation 1980-2019 .....................................29 3.1.3 Water temperature – status 2019 and trends .....................................................30 3.1.4 Water discharge – status 2019 and trends ...........................................................31 3.2 Water quality status 2019 ....................................................................................................33 3.2.1 pH and calcium .....................................................................................................33 3.2.2 Suspended matter (turbidity, SPM, and silica) .....................................................35 3.2.3 Organic carbon ......................................................................................................37 3.2.4 Nutrients ...............................................................................................................39 3.2.5 Metals ...................................................................................................................43 3.3 Additional Rivers - Water quality status 2019 .....................................................................51 3.3.1 pH and calcium .....................................................................................................51 3.3.2 Suspended matter, (turbidity, SPM, and silica) ....................................................51 3.3.3 Organic carbon ......................................................................................................52 3.3.4 Nutrients ...............................................................................................................53 3.3.5 Metals ...................................................................................................................55 3.4 Trends in riverine loads and concentrations .......................................................................56 3.4.1 Loads and concentrations of SPM, silica, TOC, and nutrients (1990-2019) ..........................................................................................................56 3.4.2 Loads and concentrations