Table 1 Overview of sampling sites in the Nidda catchment area, including the evaluation based on obtained significances
Sampling code | Coordinates | Description | Significances (%) | Category |
|---|---|---|---|---|
Nidda | ||||
N1 | 50°27′11″N 9°02′20″E | Reference site; downstream the Nidda river dam | 37.5 | Poor |
N2.1 | 50°26′40″N 9°01′57″E | Directly downstream the point of efflux of the industrial discharger | 26.7 | Moderate |
N2.2 | 50°26′36″N 9°01′47″E | Approximately 250 m downstream of N2.1 | 40.0 | Poor |
N2.3 | 50°26′29″N 9°01′43″E | Approximately 500 m downstream of N2.1 | 40.0 | Poor |
N2.4 | 50°26′26″N 9°01′34″E | Approximately 700 m downstream of N2.1 | 20.0 | Moderate |
N2 | 50°25′51″N 9°01′20″E | Downstream an industrial discharger | 45.0 | Poor |
N3 | 50°23′09″N 8°58′25″E | Downstream a class-IV WWTP (35,000 pe) | 45.0 | Poor |
N4 | 50°19′41″N 8°52′32″E | Downstream a class-III WWTP (7500 pe) | 10.0 | Good |
N5 | 50°19′08″N 8°51′28″E | Downstream the afflux of the tributary Horloff | 10.0 | Good |
N6 | 50°16′42″N 8°47′08″E | Downstream a class-IV WWTP (30,000 pe), a class-III WWTP (7000 pe), four renaturalised river sections and the afflux of the Usa/Wetter tributary | 0.0 | Very good |
Horloff | ||||
H1 | 50°31′12″N 9°02′36″E | Reference site; no direct dischargers upstream | 36.7 | Poor |
H2 | 50°30′52″N 8°57′00″E | Downstream several class-I WWTPs (< 1000 pe) | 41.7 | Poor |
H2.1 | 50°30′42″N 8°56′42″E | Approximately 500 m downstream of H2 | 46.7 | Poor |
H2.2 | 50°30′37″N 8°56′33″E | Approximately 750 m downstream of H2 | 26.7 | Moderate |
H2.3 | 50°30′18″N 8°56′24″E | Approximately 1400 m downstream of H2 | 40.0 | Poor |
H2a oh | 50°26′22″N 8°53′58″E | Upstream a class-IV WWTP | 46.7 | Poor |
H2a uh1 | 50°26′15″N 8°53′53″E | Directly downstream the point of discharge of the class-IV WWTP (78,000 pe) | 26.7 | Moderate |
H2a uh2 | 50°26′05″N 8°53′48″E | Approximately 350 m downstream H2a uh1 | 60.0 | Very poor |
H2a uh3 | 50°24′52″N 8°54′10″E | Approximately 2650 m downstream H2a uh1, following a conservation area | 53.3 | Poor |
H2a uh4 | 50°24′40″N 8°54′01″E | Approximately 3000 m downstream H2a uh1 | 40.0 | Poor |
H3 | 50°24′49″N 8°54′09″E | Downstream the class-IV WWTP (78,000 pe) | 40.0 | Poor |
H4 | 50°23′57″N 8°53′56″E | Between two renaturalised river sections | 25.0 | Moderate |
Usa | ||||
U1 | 50°19′01″N 8°31′26″E | Reference site; no direct discharger upstream | 20.0 | Moderate |
U2 | 50°22′48″N 8°42′45″E | Downstream a class-IV WWTP (50,000 pe) | 20.0 | Moderate |
U3 | 50°21′32″N 8°44′39″E | Within a renaturalised area in the city centre of Bad Nauheim | 30.0 | Moderate |
U4 | 50°20′09″N 8°46′16″E | Downstream two class-IV WWTPs (43,800/47,500 pe), and (medical) spa water discharges | 15.0 | Good |