The Effects of Wastewater Treatment Plant Failure on the Gulf of Gdansk (Southern Baltic Sea).

Marta Jaskulak,Maksymilian Sotomski,Roman Marks,Katarzyna Zorena,Małgorzata Michalska

doi:10.3390/ijerph19042048

Abstract

In August 2019 and during August/September 2020, the main collection system of the Wastewater Treatment Plant (WWTP) in Warsaw, Poland, malfunctioned. During that system failure, over 4.8 million m3 of untreated wastewater was dropped directly into the Vistula River in just a few days. It is currently considered as one of the largest known failures of WWTP worldwide. In order to assess the environmental impact, water samples were collected from 2 spots at the Vistula river estuary (406 and 415 km from the discharge location, respectively), and 4 spots at the Gulf of Gdansk, situated on the southern shore of the Baltic Sea. The sampling was conducted before the wastewater wave reached the Vistula river’s mouth, followed by daily sampling during 21 days after the malfunction occurred. The study showed the decline in water quality at the Vistula river estuary and the Baltic shore waters as the wave of wastewater reached those points, despite being situated over 400 km downstream from the place of the accident. Those changes included the reduction in the dissolved oxygen content (by 0.69-fold at its peak), the increase in Total Organic Carbon (TOC) (by 1.28-fold at its peak), nitrate-nitrogen (N-NO3) (by 1.68-fold at its peak), phosphorous (P) (by 2.41-fold at its peak), conductivity (by 16.8-fold at its peak), and Chemical Oxygen Demand (COD) (by 1.84-fold). In the samples from the Vistula river, the decline in water quality was seen as incidental and lasted 2–3 days. Subsequently, the levels of physical and chemical parameters returned to the levels from before the accident. However, the changes in the Gulf of Gdańsk lasted significantly longer, especially on the West side of the Vistula river, where, even after 21 days from the initial accident, some parameters remained altered.

Highlights

Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations
“Czajka” Wastewater Treatment Plant (WWTP) is the main wastewater treatment facility in the capital city of Poland, Warsaw [1]. It is the largest and most modern wastewater treatment facility in Poland and in Eastern Europe, collecting raw wastewater from both sides of the capital city, which is divided by the Vistula River—the largest river in Poland
At the begging of the malfunction, 3000 L of raw wastewater were released to the Vistula river every second

Summary

Introduction

Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. A temporary replacement was constructed within the following 12 days, but approximately 3,600,000 cubic meters of untreated wastewater had been discharged directly into the Vistula river, making it one of the most significant system failures of any WWTP in the world. A year later, another malfunction occurred, during which in a span of just a few days, over 4.8 million cubic meters of untreated wastewater was released directly into the Vistula River. At the begging of the malfunction, 3000 L of raw wastewater were released to the Vistula river every second. Given the sheer volume of raw wastewater released to the river, both failures of this WWTP were one of the largest WWTP accidents in the world. We presented the results of the research in several manuscripts [12,13,14,15]

Methods

Discussion

Conclusion