Ecological, Socio-Economic and Demographic Analyses As

Vol. 149, No. 2-3 · Research article

Ecological, socio-economic and demographic analyses as DIE ERDE prerequisites for sewage treatment Journal of the Geographical Society problem solutions in rural areas. of Berlin The case study of Dirlammen, Vogelsberg, Germany

Christian Opp1, Bastian Ziebolz2 and Michael Groll1

1 Faculty of Geography, University of Marburg, Deutschhausstr. 10, D-35032 Marburg, Germany, [email protected] ² KLT Consult Hannover/Soest, Lippestr. 2, D-59510 Lippetal, Germany, [email protected] ³ Faculty of Geography, University of Marburg, Deutschhausstr. 10, D-35032 Marburg, Germany, [email protected]

Manuscript submitted: 11 November 2017 / Accepted for publication: 10 April 2018 / Published online: 27 September 2018

Abstract The municipal sewage treatment in Germany is traditionally centralized and allows for a high disposal se- curity. The implementation of the EU Water Framework Directive (EU-WFD) showed that the central target, the so-called ‘good ecological state’ has not yet been reached in 90% of all surface water bodies. A common and widespread measure to reach said target is the improvement of sewage treatment plants (STP). A large part of the expenses for that has to be shouldered by local communities. But many rural communities already have to manage high costs caused by the modernization of the sewage pipe system. And as the size of the rural population decreases continuously, the per capita burden increases. This raises the question whether the construction of a new sewage treatment plant is the most efficient way to improve the water quality in rural areas. A comprehensive approach has been developed for answering this question, consisting of 1) biological and physico-chemical wastewater analyses, 2) a modified eco-balance for the construction of a new STP and 3) socio-economic and demographic population analyses. The results show that the water quality of the studied creek is good with exception of the sewage disposal point. The eco-balance for the construction, the operation, and the environmental side effects show that the continued operation of the existing STP is more effective than the construction of a modern facility. This conclusion is supported by the aging and general decrease of the rural population. The diminishing potential to shoulder additional costs is in contrast to the reduced future demand for a modern STP.

Zusammenfassung Die kommunale Abwasserbehandlung erfolgt in Deutschland traditionell zentralisiert. Das garantiert eine hohe Entsorgungssicherheit. Die Implementierung der EU-Wasserrahmenrichtlinie (EU-WRRL) hat gezeigt, dass das

ModernisierungHauptziel, der „gute der ökologischeAbwasserreinigungsanlagen. Zustand“, in den meisten Ein Großteil Oberflächenwasserkörpern der Kosten für diese Maßnahmen (90%) noch wird nicht dabei erreicht von wurde. Eine weitverbreitete Maßnahme, den ökologischen Zustand von Fließgewässern zu verbessern, ist die

Christian Opp, Bastian Ziebolz, Michael Groll 2018: Ecological, socio-economic and demographic analyses as prerequisites for sewage treatment problem solutions in rural areas. The case study of Dirlammen, Vogelsberg, Germany. – DIE ERDE 149 (2-3): 184-197

DOI:10.12854/erde-2018-369

184 DIE ERDE · Vol. 149 · 2-3/2018 Ecological, socio-economic and demographic analyses as prerequisites for sewage treatment problem solutions in rural areas. The case study of Dirlammen, Vogelsberg, Germany

- den Kommunen getragen. Gleichzeitig finanzieren die ländlichen Gemeinden die teure Modernisierung des Ab- wasserleitungssystems, während die Bevölkerungszahl in vielen ländlichen Gemeinden kontinuierlich abnimmt. wurdeDeshalb im bestand Untersuchungsgebiet die zentrale Zielstellung ein integrierter dieser Untersuchungsansatz Studie darin, herauszufinden, bestehend ob aus: der 1) Bau einer einer biologischen neuen Abwas und serreinigungsanlage der effizienteste Weg ist, die Wasserqualität im ländlichen Raum zu verbessern. Hierfür- physikochemischen Abwasseranalyse, 2) einer modifizierten Öko-Bilanz für den Bau einer neuen Abwasser- reinigungsanlage sowie 3) einer sozio-ökonomischen und demographischen Bevölkerungsanalyse verfolgt. Die derAbwasseranalysen Umweltnebenwirkungen ergaben, dass zeigten, die Wasserqualität dass der Weiterbetrieb im Fließgewässer der existierenden mit Ausnahme Abwasserreinigungsanlage des Abwassereinleitungs ef- abschnitts gut ist. Die Ergebnisse der Öko-Bilanz unter Einbeziehung der Bau- und Unterhaltungskosten sowie-

Gegensatzfizienter ist zu als dem der in Bau Zukunft einer neuensinkenden Anlage. Bedarf Dieser für Schlusseine moderne wird auch Abwasserbehandlungsanlage. durch die Überalterung und den Bevölke rungsrückgang in der Gemeinde gestützt. Das schwindende Potential, zusätzliche Kosten zu schultern, steht im Keywords

sewage treatment, rural areas, ecological analysis, eco-balance, demographic analysis

1. Introduction

The Water Framework Directive of the European native and more affordable way to improve the water sidequality effect of of rivers river and restoration creeks ismeasures the enhancement (Diehl 2004; of Grollthe self-purification and Opp 2007). potential,Due to their which smaller is a catchment beneficial forUnion all surface(EU-WFD), and which groundwater was ratified bodies in is the the year so-called 2000, - is a tool to improve the water quality. The main target- - tion until 2027) (EU areas and smaller length, creeks possess an only lim ‘good ecological ecological status’ state’ untilas the 2015 combination (and by prolongaof chemi- ited ability for self-purification and dilution of pol- 2000). The EU-WFD defines the lutants. Settlements in the upper catchments usually- - solely have access to pond sewage plants with a re cal quality conditions (defined by standards for the processesduced purification and are, capacity. due to Thesetheir pondcost-effectiveness, sewage treat maximum concentrations of specific water pollut thement most plants common are based wastewater on microbial treatment self-purification technol- ants) and biological quality conditions (assessed via- - indicator species such as fish, benthic invertebrates, Borchard and Menadi 2001; LfU 2006). But at the nutrientor macrophytes concentrations). in combination While the with non-point physico-chemi impacts ogy in less densely populated rural areas in Germa cal quality conditions like temperature, oxygen, and treatmentny ( plants is limited. According to the German the effects of point sources are much easier to assess. wastewatersame time, the ordinance purification (AbwV result 2004 in the pond sewage on water bodies are extremely difficult to monitor,- art technologies for wastewater disposal), which in depend defines- reductionTherefore, of the the many harmful activities pollutants aimed from at the these improve point encethe purification on the population requirements equivalent, based the ventilated on state of pond the sourcesment of ( theBruch water 2002). quality The construction are directed and towards operation the sewage plant in Dirlammen meets the requirements of sewage treatment plants (STP) in combination with of level 1 (up to 1,000 population equivalents) and level 2 (up to 5,000 population equivalents) (c.f. Photos 1 and pollutant thresholds has led to a considerable im- and 2 issuing and enforcing wastewater quality standards technique is suitable enough for the carbon depletion since the 1960s (Kessler 2004). (CSB, ).BSB5), While the this Dirlammen means that STP this is simplenot equipped purification to fa- provement of the water quality in the EU countries Therefore, the discharged treated water still contains residuescilitate direct of various nitrification pollutants and and fertilizer contributes elimination. to the (TheSeeger German 1999) municipaland provides sewage a reliable treatment disposal system secu- is characterizedGWP 2009). Studies by a high conducted degree in of the centralization 1990s also downstream. In order to solve this problem, the con- structionimpairment of of modern the water sewage quality treatment of rivers andplants streams is a rity ( - - showed that any further improvement of the water qualityDIE ERDE would · Vol. 149require · 2-3/2018 huge financial costs. An alter popular demand of many politicians and environmen185 Ecological, socio-economic and demographic analyses as prerequisites for sewage treatment problem solutions in rural areas. The case study of Dirlammen, Vogelsberg, Germany

- 2. Study area nities and the often larger distances to the next STP, talists. Due to the smaller size of many rural commu - average per capita fees for the maintenance and op- - erationthe rural of populationthese wastewater often has treatment already tofacilities pay above and The problem outlined above is typical for the com for the rehabilitation of the household’s sewage pipe Hessemunity ( Photosof Dirlammen 1 and 2 ).within Lautertal the municipality has a population of Lau of tertal in the Vogelsberg district of the federal state of average wastewater fee is 4.81 €/m³ (excluding addi- km². Dirlammen itself has a present (2017) popula- system. In the Vogelsberg district, for instance, the tion2,424 of and 381 a within population 140 households, density of 45 each inhabitants of them with per while the average fee in the rural Lautertal munici- tional costs for the rehabilitation of the pipe system)3 (RPGI (1970: 425, 2007: 413, 2012: 404, 2013: 391, 2014: 2017). The construction of new STPs would add an an average of two toilets. The population dynamics pality (in the Vogelsberg district) is 6.00 €/m 3 freshwater389, 2015: 390,(and 2016:wastewater) 392) show per inhabitant. a falling tendency. Dirlam- additional financial burden onto the rural population,- menThe communityis located at members 453 m a.s.l. use and on averagecovers an 35-40 area mof creasingwhich seems for decades unreasonable, and will especially continue asto thedo sosize in andthe 53.61 km2 (HSL futuredensity ( HSLof the 2007-2012; population BBSR in rural 2017). areas Therefore, has been the de in- vestments for the construction of new sewage treat- 2012). Since 1987, the municipality of - EuroLautertal for the operates construction an oxygenated and operation pond ofsewage the present plant ties and alternative solutions are needed. STP,in Dirlammen. which has notThe been community upgraded has since invested construction. 287,000 ment plants cannot be covered by the rural communi Among the total of 707 STPs in the Federal State of DWA 2016). It consists

oneHesse, maturation 133 belong pond to this with type a shallow( water zone for treatingof two connected the mixed oxygenated domestic wastewaterwastewater andponds storm and water (Photo 3 have a water depth of 2.50 m and a combined surface area of 896.5 m).2 Both(Photo oxygenated 4). The maturation wastewater pond ponds has a depth of one meter and a surface area of 360 m2 (Photo 5).

Photo 3 Pond sewage plant in Dirlammen. Source: Own elaboration, based on Google Maps 2013

Photo 1 and 2 The rural area of the municipality Lautertal (top) and the community of Dirlammen (bottom) within the Vogelsberg District, Federal State of Hesse, Germany. Photo credit above: B. Ziebolz 2016, photo credit below: aerial photo, Ziebolz 2016: 3 (unpub- lished), based on Renker 2005

186 DIE ERDE · Vol. 149 · 2-3/2018 Ecological, socio-economic and demographic analyses as prerequisites for sewage treatment problem solutions in rural areas. The case study of Dirlammen, Vogelsberg, Germany

Dirlammen STP is based on the principles of biological The wastewater treatment technologyRöske and used Uhlmann in the 2005). Like in natural water bodies, bacteria consum- self-purification in water bodies ( - ganic components of the raw sewage. The growing ing oxygen desintegrate the easily biodegradable or transforms it into mineralized products of the biodeg- radationbacteria biomass(water, utilizescarbon thedioxide, biochemical ammonium, energy phos and- -

phate), which, in turn, form the basis for the photosyn ofthetically the excess active mass phytoplankton. of bacteria and The algae oxygen is consumed produced by the plankton is then usedDaphnia by bacteria. sp.), which A large causes part Photo 4 First and second air conditioned pond of the pond Röske and Uhlmann sewage plant in Dirlammen. Photo credit: C. Opp by zooplankton (especially - 2017 a substantial purification effect ( - 2005). Due to the limitations of this process, nitrifica tion, denitrification, and phosphorus elimination can not be achieved by the Dirlammen STP.

revealedIndependent high waterammonia quality loads measuring with a clear campaigns exceedance in ofthe the Brenderwasser corresponding Creek threshold. during theAlso, past the years sampled have macrozoobenthos species indicated an impaired wa- - stream of the sewage disposal point, while the water ter quality. Both of these deficits were detected down - quality recovered gradually with a greater distance- ingfrom low the water wastewater periods, inflow. when Thedilution lowest processes water qual are ity values in the BrenderwasserRP Gießen 2008). were This detected point source dur Photo 5 The maturation pond of the pond sewage plant in pollution put plans for a replacement of the old pond Dirlammen with algae growing during July. Photo severely limited ( credit: C. Opp 2017 sewage plant with a new sewage treatment facility on the agenda. But both the community of Dirlammen €6,000 5,700 means for such an investment. Furthermore, the lo- and the municipality of Lautertal lack the financial €5,000 4,750 €4,000 3,800 regularcal population sewage hascosts already (Fig. 1 had to contribute to the rehabilitation of the sewage pipe system on top of the €3,000 2,850 ), making any additional €2,000 1,900 Overall,financial the burden construction infeasible. of a new STP would not be 1,022 €1,000 950 851 511 681 170 340 €0 the local population, while such a modern STP could 500m² 1000m² 1500m² 2000m² 2500m² 3000m² affordable by the municipality, the community, and- Pipe system rehabilitation costs per household 2010 in € creasing population. Hence, a modern STP would not Annual sewage costs per household in € not operate at full capacity, given the continuously de Fig. 1 Additional sewage costs per household for the rehabilitation of the sewage pipe system 2010 (yellow) and fulfill the cost-efficiency requirement of the EU-WFD. annual sewage costs (red) in dependence of the plot area. Source: Own elaboration, based on community information

DIE ERDE · Vol. 149 · 2-3/2018 187 Ecological, socio-economic and demographic analyses as prerequisites for sewage treatment problem solutions in rural areas. The case study of Dirlammen, Vogelsberg, Germany

3. Objectives, approach, and methods -

Based on these problems, multiple research ques- conductedthe sewage four disposal times point, during analyzing spring (22 the spatialMarch, ex26 tions, objectives, and methods were selected for this tent of the wastewater influence. The monitoring was

April) and summer (21 June, 12 July) of 2010 during case study. Due to the fact that the water quality data varying seasonal water level and discharge conditions had been collected several years before this study of the Brenderwasser Creek, analyzing the influence was conducted, it was necessary to assess the present of the hydrology on the water quality. Continuous status quo of the creek’s pollution caused by the pond- themeasurements little creek. wereWith notthe help possible of this because multi-temporal of partly sewage plant Dirlammen. The first step in thisPottgiess regard- strong fluctuations within the low water segment of- erwas and a preliminary Sommerhäuser analysis (2008), of thethe riverbedwater body structures charac ing, it became possible to evaluate the impact of the basedteristics, on especiallyGroll and Opp the (2007),river type Groll based on pondand spatially sewage plant differentiated Dirlammen water on the quality status quo monitor of the Groll Brenderwasser Creek (Fig. 2). the saprobic indicator species of the et al. macrozooben (2016), and- thos (after(2017). Klee This 1998 was and followed Meier by2006). the assessment The faunistic of The four sampling points (SP) along the Brenderwas- sampling and the taxonomic determination of the ser Creek were located near the settlement of Dirlam- macrozoobenthos were conducted in accordance with men, with SP1 being 200 m upstream of the STP out- the updated guidelines for the assessment of the saprobic index (DIN chemical monitoring of the creek’s water was carried locatedlet, SP2 900 being and located 2,200 m directly downstream 50 m downstream of the STP out of- out at four sampling 2004). points This in different biological distances and physico- from let.the STP outlet, followed by SP3 and SP4, which were

Fig. 2 Research approach (questions, methods, and objectives). Source: Own elaboration

188 DIE ERDE · Vol. 149 · 2-3/2018 Ecological, socio-economic and demographic analyses as prerequisites for sewage treatment problem solutions in rural areas. The case study of Dirlammen, Vogelsberg, Germany each of these four sampling points included the fol- lowingThe water parameters: quality monitoring water temperature program (°C), carried pH-value, out at fication (both with a high ecological priority) as well- - as the energy demand and direct disturbances of the - potentialaquatic ecosystem new STP (withand for a moderatethe existing ecological pond sewage prior electric conductivity (EC, µS/cm), oxygen concentra ity). All of these parameters have been analyzed for a tration of various nutrients (NH3, NH4, NO2, NO3, total treatment plant. In both cases, scenarios for operating tion (mg/l) and saturation (%) as well as the concen WTW 2016) and followingphosphorus), the all federal of which water were agreement analyzed on regulations site using times of 15 and 30 years have been analysed. (aLAWA-AO WTW multi-parameter 2007). In addition field to these kit ( parameters, the with the help of the computer software GEMIS (Global These analyses and evaluations were carried outII- the SPs using the Poleni formula (Bollrich 2007). NAS - discharge (l/s) was determined at spillways next to Emission Model Integrated System), version 4.5 ( - sources,2018). the The thermal GEMIS and database electric for power, this study building con materials,tains information and transport about: processes. the allocation For example, of energy the Discharge and water temperature influence the sol emissions of greenhouse gases and the utilization of ubility of various pollutants and, thus, control the- resources were determined pro rata for the produc- self-purification processes of the creek. The pH value ofcontrols organic the material abundance and andin consequence vitality of the the benthic self-puri or- ganisms, which in turn influence the decomposition fortion the and mining the operation and production of a chain of dredger sand, split, and agravel, lorry, an indicator of the total ion concentration, is a meas- for the production of cement flagging, and screed or fication processes. The electric conductivity (EC), as - andbasaltic scenarios. crushed For sand, all thesebricks, processes, and polyethylene the database pips. ure of the pollution influx from the STP. The nitrogen,- GEMIS calculates so-called life cycles for all processes cessesphosphorus along andthe creek.oxygen values are used for the evalu output and life time, the direct airborne pollutants, ation of the effectiveness of the self-purification pro thespecified greenhouse the degrees gas emissions of efficiency as well and as utilization, the solid andthe liquid residual materials. With the help of GEMIS, the a new STP versus the continued operation of the old In order to assess the viability of the construction of the aggregation of resources in form of a cumulated on the studies of Klöpfer and Grahl (2009) was devel- assessment of environmental analyses, for example- one, an eco-balance (or life cycle assessment) based mate became possible (IINAS 2018). energy demand or of harmful substances for the cli oped. A simple life cycle includes the following steps: - the primary raw material and energy production,- ment of socio-economic questionnaires in accordance tionthe semi-finishedas well as all production,transport impacts the final between production, these toThe Schnell final (1999) step of and the interviews study design with was the the local develop inhab- stepsthe usage, (IINAS and 2018). the With clearance the help respectively of the eco-balance, reclama itants, which were carried out for the assessment of it is possible to detect the environmental impacts

Schmitz and Paulini 1999). An the age-related and employment-related population eco-balancecaused by the according production, to EN technologies, ISO 14044 (2006) and services is com- (structureFig. 1). as well as for the monetary potential of the prisedutilized of by the any following project components:( 1) determination locals to pay for higher wastewater treatment costs of the objective(s) and the framework, 2) balance of substances, 3) evaluation of the effects and 4) assess- 4. Results ment. In this case, the eco-balance contains the determination of the production costs of a new STP, includ- ing the material costs, and the costs for the operation. Details of the used methods 2), 3) and 4) are described 4.1 Physico-chemical and biological analyses - Schubert (2006). Furthermore, the eco-balance ac- er of the lower mountain range”; Döbbelt-Grüne cording to Klöpfer and Grahl (2009) includes the com- The Brenderwasser Creek is a type 5 river (“small riv parisonby and evaluation of additional environmental et al. 2014: 78). Rivers of this type are characterized by - coarse, silicate sediments. This was confirmed by the side effects, such as the greenhouse effect (with a very riverbed analysis, which revealed a clear dominance highDIE ERDE ecological · Vol. 149 priority), · 2-3/2018 the summer smog and acidi of coarse gravel and pebbles at nearly all sampling189 Ecological, socio-economic and demographic analyses as prerequisites for sewage treatment problem solutions in rural areas. The case study of Dirlammen, Vogelsberg, Germany

The lowest EC values were measured at SP1 (upstream the STP outlet) during all times. The electric points, while organic materials were detected in only small quantities (< 5%). The sampling point nearby- erbed),the STP which outlet coincided (SP2) showed with the a significantlydominance of higher Asse- conductivity in March, April, and June was around lusamount aquaticus of organic, a faunistic material indicator (covering for bad 15% to of mediocre the riv The150 µS/cm,strong whileimpact in of July the it STPwas on350 the µS/cm. Brenderwasser - Creek was also detected in the NH3-N (Fig. 4) and NH4-N concentrations. Both nitrogen concentrations water quality. All the other sampling sites wereFig. char 3). showed the same distribution pattern with the lowest acterized by species indicating a good water quality concentrations recorded at SP1, the maximum at SP2, characteristic(quality class 2; seasonal saprobic changesindex of 1.79-1.90,(Fig. 4). Whilecf. the The discharge and temperature dynamics reflect towards SP4. Phosphorus also showed the highest followed by a gradual decrease of the concentration pH-values (7.2-8.4) did not fluctuate very much over time, the electric conductivity (EC) showed a steady concentrations throughout the year at SP2 with strong treatedincrease wastewater. from March There, to July. the The EC highest ranged overall between EC fluctuations between 0.3-0.6 mg/l from March to June values were detected at SP2, near the inflow of the and a very high concentration of 3.2 mg/l during the dischargelow-flow situation (Photo 6 in July. This is a consequence of the- 170 and 240 µS/cm in March, April, and June and- trationreduced and dilution saturation capacity reached during their periods minimum of very values low reached 730 µS/cm in July. 2,200 m downstream (SP4) ). Furthermore, the oxygen concen- of the STP, the electric conductivity in July was consid centrations were detected in March (12.0 mg/l and (cf.erably Fig. lower 4), the (375 Brenderwasser µS/cm). Although Creek the was discharge able to di in- at SP2, near the STP outflow. The highest oxygen con luteJuly wasthe veryion load low andcoming the waterfrom thetemperature STP point was source. high 100%) while the minima were registered in July.

Fig. 3 Saprobic Index (SI), species abundance classes (A), ecological quality classes, and macrozoobenthos dominance along the sampling points (SP1-SP4) in the Brenderwasser Creek near Dirlammen. Source: Own elaboration, based on HVBG 2017

190 DIE ERDE · Vol. 149 · 2-3/2018 Ecological, socio-economic and demographic analyses as prerequisites for sewage treatment problem solutions in rural areas. The case study of Dirlammen, Vogelsberg, Germany

Fig. 4 Ammonia concentration at the four sampling sites during four measuring times along the Brenderwasser Creek near Dirla- mmen (SP2 50 m downstream of the sewage treatment plant). Source: Own elaboration

Photo 6 Low discharge of the Brenderwasser Creek in July 2017. Photo credit: C. Opp 2017

DIE ERDE · Vol. 149 · 2-3/2018 191 Ecological, socio-economic and demographic analyses as prerequisites for sewage treatment problem solutions in rural areas. The case study of Dirlammen, Vogelsberg, Germany

greenhouse emissions (CO2 -

4.2 Eco-balance (life cycle assessment) operation) in comparison to-equivalent) the continued by 299%operation (af based on a comparison of the operation of the exist- ofter the 15 yearsold STP. of operation)The according and 184%values (after for the 30 summeryears of ingThe pond eco-balance STP Dirlammen approach with used the in construction this study wasand operation of a new sewage treatment plant. The BIO- smog effect are an increase of 852% (after 15 years COS (Biological Combined System 2004) STP in Wahlen 2-equivalent) would be (Fig. 5 of operation) and 461% (after 30 years of operation) Because of its size (575 population equivalent) and while the acidification (SO ) represents an already existing modern STP. 567% (after 15 years of operation) and 318% (after 30- tionyears and of operation)operation ofhigher a new for STP the compared new STP comparedto the old the novel process technology, the BIOCOS sewage to the old one. The energy demand for the construc suitedtreatment as a plantcomparable in Wahlen example (part for of the the potential municipality new Fig. 6). Overall, the ecologi- of Kirtorf, Federal State of Hesse, Germany) is well calone side-effectswould be 212% of the higher construction after 15 of years a new and STP 141% get data for the eco-balance of the Dirlammen STP have lesshigher severe after the 30 longer years the(cf. new plant is operational, but beensewage extracted plant in from Dirlammen. the BIOCOS Therefore, STP in Wahlen.all necessary

even after 30 years of operation the new STP would

Fig. 5 Flowchart of a BIOCOS sewage treatment plant. Source: Own elaboration

still have a worse eco-balance than the continued op- - eration of the existing STP. Among all the parameters Due to the very high costs for a newly constructed STP,- it is not efficient to construct a new one in compari environmentalson with the continued side-effects operation of the of old an STPalready compared estab caseanalyzed, of the only continued the direct operation disturbances of the old of STPthe inaquatic com- tolished the effectspond STP. of a However, new one. it All is ofinteresting the above to mentioned study the parisonecosystem to theare construction higher (by 18% of a afternew STP. 30 years) in the ecological side-effects (except the direct disturbances load through the construction and operation of a new of the aquatic ecosystem) cause a distinct additional and operation of an STP leads to an increase of the STP. The additional load caused by the construction 192 DIE ERDE · Vol. 149 · 2-3/2018 Ecological, socio-economic and demographic analyses as prerequisites for sewage treatment problem solutions in rural areas. The case study of Dirlammen, Vogelsberg, Germany

Fig. 6 Comparison of the old and a newly constructed sewage treatment plant regarding the additional load through selected effect categories for further 30 years of operation. Source: Own elaboration, based on Klöpfer and Grahl (2009)

aging (IKEK 2013). Thus, based on this projection, the 4.3 Socio-economic and demographic analyses - totalage group population older than in 2050 65 years could will be asgrow small as asa result 296 for of Dirlammen (at present: 419) and 1,343 for Lautertal The questionnaire revealed that 54% of the inhabit (at present: 2,514). The continued depopulation of the ants (226 of 419) of the community Dirlammen are- rural communities will lead to a considerable reduc- retired. 17% are working in the service sector, 13% in- tion of the resultant wastewater (cf. Hillenbrand the public survey sector, 10% in the production sec- 2010). Due to the fact that the existing sewage pipe tor, 3% in the construction sector and 3% in agricul et al.- ture. This is a very common retirement and employ 30ment households, structure equalingfor rural areasone third in Germany. of the inhabitants, system must be maintained regardless of the popula - tion relying on it, these costs have to be shouldered uals expressed their protest against additional costs evenby fewer without people. the Thus construction the individual of a new financial STP. This burden and took part in the study. 93% of all interviewed individ thewill expectedsignificantly under-utilization increase during of the the next existing decades STP – - caused by a new STP. 3% would even leave the village- tion.as they could not afford the additional financial bur (caused by the reduced amount of wastewater) render den, while another 4% chose to not answer this ques any plan for the construction of a new STP non-viable. In consequence of the ongoing demographic develop- 5. Conclusion ment (WeKaDe 2017), a considerable decrease of the Based on the results mentioned above, the continued operation of the existing pond sewage plant in Dir- thepopulation next decades. both in Between the community 2000 and of Dirlammen2010, the total and lammen can be recommended (Fig. 7). Pond sewage in the municipality of Lautertal is expected during - population number decreased by 8.3% in Dirlammen plants can eliminate 80-90% of the BOD (Biochemical- and by 14.5% in Lautertal. Projecting this trend into mentOxygen (Goad Demand) and reduce bacteria to levels com the future, by 2030 Lautertal will have lost another parable to other accepted oxidation types of treat (20%WeKaDe of its population (-500 inhabitants), while the communities 2017). due to Therefore, low construction this type costsof treatment as well agingdecrease and inemigration. Dirlammen Among will bethe approximately emigrants, the 14% age minimalsystem meets operation the needsand maintenance of many small requirements. and/or rural A 2017). This downward trend is caused by - group of young people (<20 years old) dominates. modern STP would improve the water quality in areas 40% or 250 of the 450 persons in this age group will- the old pond sewage plant cannot (nitrification, deni- probably migrate to larger cities until 2030. The age trification, and phosphorus elimination), but the eco- groups 20-45 and 45-65 will also be affected by a sig balance shows that this additional gain in the purifi nificantDIE ERDE reduction · Vol. 149 · 2-3/2018 during that time frame. Only the cation is canceled out by the ecological (and financial)193 Ecological, socio-economic and demographic analyses as prerequisites for sewage treatment problem solutions in rural areas. The case study of Dirlammen, Vogelsberg, Germany impacts of the construction of such a modern STP. It concluded that, based on the amount of wastewater - theseems demographic to be more development efficient to delivers improve a the strong purifica eco- constructionin the small of community, a new sewage the decreasingtreatment plant population is not nomiction technology argument of against the existing such anpond investment. STP, especially Options as advisable.number, and This the indicates financial thatsituation the resultsof Eichelhain, presented the to improve the existing technology are for instance: here are of general importance for many rural areas treatment;retrofitting reorientation the mechanic of pre-cleaningthe water levels and in primaryorder to objective,in Germany. but The the elaboration results show of athat long-term the future affordable demo- treatment for the release of the (biological) tertiary- graphicwastewater development treatment must concept also be is taken a highly into relevant consid- rus precipitation step for the reduction of phosphorus eration. For choosing the right wastewater treatment concentrationsprevent backwater and thecurrents; organic retrofitting load; the emplacement a phospho

- for rural areas, the water quality analyses have to be of additional sedentary soils for the immobilization of- complemented by an eco-balance,Fig. 7) socio-economic can lead to respon and- faces,the biomass; guidance the walls installation and scum of a boards reflux systemfor improving for re demographic analyses. Only such a comprehensive peated purification or the installation of impact sur improvementsanalysis and evaluation of existing (cf. sewage treatment plants, andsible aboutdecisions the aboutpotential the maintenanceconstruction and of necessarynew sew- the flow conditions. Pfeiffer (2013) in age treatment plants. One important consequence of Pfeiffer (2013) used theSimilar same results research were approach presented and by methods in anoth- - eranother sub-catchment rural case of studythe Lauter area. River, the Eisenbach pendantthe observations measure and categories: evaluations 1) immediate of the pipe rehabili system- - tation,in Dirlammen 2) short-term was the rehabilitation, definition of four3) medium-term damage-de Pfeiffer rehabilitation, and 4) long-term rehabilitation. Up to catchment, and analyzed the Eichelhain pond STP. In dependently from the Dirlammen case study,

Fig. 7 Results of the trilateral analyses and comprehensive interpretation. Source: Own elaboration

194 DIE ERDE · Vol. 149 · 2-3/2018 Ecological, socio-economic and demographic analyses as prerequisites for sewage treatment problem solutions in rural areas. The case study of Dirlammen, Vogelsberg, Germany

- Stadt- und Raumforschung. – Online available at: http:// dation for immediate and short-term rehabilitation measures.now, the community Based on hasthat, implemented there is a residual the recommen demand Sonderveroeffentlichungen/2017/rob-2017.html, www.bbsr.bund.de/BBSR/DE/Veroeffentlichungen/ for rehabilitation measures of about 1.1 million Euro accessed 09/11/2017 (Theilen BIOCOS (Biological Combined System) 2004: Biological for Research on Building, Urban Affairs and Spatial – Online available at: http://www. Developmentet al. (2014).BBSR 2017)A report furthermore of the Federal discusses Institute the geoportal-wasser.rlp.de/servlet/is/8343/Belebungsanlage Combined System. change from a centralized to a decentralized waste-

%20nach%20dem%20BIOCOS-Verfahren_KA%20 would result in the decommission of the existing pond accessed 31/01/2016 Breunigweiler%20%28VG%20Winnweiler%29.pdf, water system as one option in remote rural areas. This Bollrich, G. biological sewage facilities. But the same report also 2007: Technische Hydromechanik. Bd. 1. – system and the establishment of a number of smaller Borchard, D. and F. Menadi 2001: Empfehlungen für Berlin/Germany - die Errichtung und den Betrieb von belüfteten waterdiscusses treatment the social in rural and political areas might difficulties be the joining of such of a system change. Another option for the future waste Teichkläranlagen. – Institut für Gewässerforschung und However, it remains unclear if such measures and/ Gewässerschutz (IAG), Universität Gesamthochschule orwastewater the reduced pipe wastewater systems of treatment neighboring demand settlements. due to Bruch, I. 2002: - Kassel. – Kassel/Germany the demographic change can lead to lower costs for fenheit und Frachten diffuser und punktueller Stick- Räumliche Variabilität der Wasserbeschaf the operation and maintenance of the technical infra- - stoffeinträge in kleinen Einzugsgebieten des Saarlands. administrations has to be to promote (re-)immigra- chen Raum. structure. Therefore, one task of the rural community Beitrag zu Abwasserbehandlungskonzepten im ländli – PhD Thesis, Department of Geography and Diehl, H Geosciences, Universität Trier. – Trier/Germany tion of younger people into the rural communities in und Strukturverbesserung durch Totholz. – Marburger . 2004: Erfahrungen bei der Gewässerentwicklung order to strengthen their financial base. Geographische Schriften 140: 142-154 Acknowledgements DIN (Deutsches Institut für Normung) 2004: Normausschuss Wasserwesen DIN 38410-1. Deutsche Einheitsverfahren The authors want to thank the administration and the in- zur Wasser-, Abwasser- und Schlammuntersuchung – - M) – Teil 1: Bestimmung des Saprobienindex in Fließge- habitants of the Dirlammen community within the Laut Biologisch-ökologische Gewässeruntersuchung (Gruppe ertal municipality, and especially the mayor, Heiko Stock, Döbbelt-Grüne, S., C. Hartmann, U. Zellmer, C. Reuvers, for their cooperation during the study and for the upgrade wässer (M1). Stand 10/2004. – Berlin/Germany C. Zins and U. Koenzen information. We separately thank Frank Reißig (Regional support and advice regarding the eco-balance application Council Giessen, Department IV, Germany) for his continued 2014: Hydromorphologische and information about the status quo and ongoing discus- Steckbriefe der deutschen Fließgewässertypen – Anhang Renaturierungsmaßnahmen und ihrer Erfolgskontrolle. 1 von Strategien zur Optimierung von Fließgewässer We thank Frank Renker for the aerial sions about the future of the wastewater purification in the photograph (Photo 2). DWA (Deutsche Vereinigung für Wasserwirtschaft, Abwasser Vogelsberg district. UBA-Texte 43/2014. – Dessau-Roßlau/Germany und Abfall = German Association for Water, Wastewater and Waste) DWA Landesverband Hessen/Rheinland-Pfalz/ References Saarland (ed.) 2016: Nachbarschaften im DWA Landes- verband Hessen/Rheinland-Pfalz/Saarland. Nachbar- AbwV (Abwasserverordnung - – Mainz/ - ) 2004: Verordnung über An schaftslisten mit Erläuterungen. Teil Hessen. EN ISO 14044. 2006: Normenausschuss Grundlagen forderungen an das Einleiten von Abwasser in Gewäs Germany – des Umweltschutzes (NAGUS) - DIN EN ISO 14044. ser. Anhang 1: Häusliches und kommunales Abwasser. – Online avalailable at: http://www. Umwel Bundesministerium für Justiz und Verbraucherschutz, gesetze-im-internet.de/abwv/anhang_1.html, accessed Berlin/Germany. tmanagement – Ökobilanz – Anforderungen und 13/12/2017 EU (European Union) 2000: Directive 2000/60/EC of the Anleitungen. Stand 2006. – Berlin/Germany BBSR (Bundesinstitut für Bau- Stadt-und Raumforschung) European Parliament and the Council of 23 October 2000 2017: Raumordnungsbericht des Bundesinstituts für Bau-

establishing a framework for community action in the DIE ERDE · Vol. 149 · 2-3/2018 195 Ecological, socio-economic and demographic analyses as prerequisites for sewage treatment problem solutions in rural areas. The case study of Dirlammen, Vogelsberg, Germany

Oberirdische Gewässer und Küstengewässer) P 0001-0073. – Brussels/Belgium 2007: Rahmenkonzeption Monitoring. Teil B: field of water policy. – Official Journal L327, 22/12/2000 Goad, M.E. 2017: Introduction to wastewater treatment Bewertungsgrundlagen und Methodenbeschreibung. ponds. – Online available at: http://www.waterworld. Arbeitspapier 2. Hintergrund- und Orientierungswerte com/articles/print/volume-27/issue-10/editorial- features/introduction-to-wastewater-treatment-ponds. available at: https://www.umweltministerkonferenz.de/ für physikalisch-chemische Komponenten. Online html, accessed 12/12/2017 umlbeschluesse/umlaufBericht2007_25.pdf, accessed Groll, M. 2017: The passive river restoration approach as an 22/08/2018 LfU (Landesamt für Umweltschutz Sachsen-Anhalt) 2006: Abwasserteichanlagen zur kommunalen Abwasserrei- efficient tool to improve the hydromorphological diversity in the German lower mountain range. – nigung (Hinweise zu Planung, Bau, Betrieb und Optimie- of rivers – case study from two river restoration projects 293: 69-83, doi:10.1016/j.geomorph.2017.05.004 rung). Fachbereich 2 Abfallwirtschaft, Bodenschutz, An- Geomorphology Groll, M. and C. Opp lagentechnik Wasserwirtschaft. Habitate in einem renaturierten Abschnitt der Lahn. Meier, C. - 2007: Gewässerbettmorphologie und – Halle/Germany wertung. Handbuch zur Untersuchung und Bewertung 2006: Methodisches Handbuch Fließgewässerbe Naturschutz und Landschaftsplanung 39: 369-376 Exemplarische Anwendung des TRiSHa-Verfahrens. – Groll, M., A. Thomas, L. Jungermann and K. Schäfer 2016: vor dem Hintergrund der EG-Wasserrahmenrichtlinie. – von Fließgewässern auf Basis des Makrozoobenthos , a new method for a high resolution characterization of the accessed 21/01/2016 Typology of Riverbed Structures and Habitats (TRiSHa) – Online available at: www.fliessgewaesserbewertung.de Pfeiffer, I. 2013: –Ecological Indicators 61: 219-233, doi:10.1016/j. spatial and temporal dynamic of freshwater ecosystems. Ökobilanz eines Kläranlagenbaus und ecolind.2015.09.019 untersuchungen als Grundlage für weitergehende Pla- saprobielle sowie physikalisch-chemische Gewässer- GWP (German Water Partnership) (ed.) 2009: Excellence - ter besonderer Berücksichtigung des demographischen nungen am Beispiel der Teichkläranlage Eichelhain un capacities, organizational structures and actors. – Berlin loma-Thesis. – Fach- in water technology & water management. Booklet on = www.germanwaterpartnership.de (CD) - Wandels im ländlichen Raum. Dip Hillenbrand, T., J. Niederste-Hollenberg, E. Menger-Krug, S. bereich Geographie, Philipps-Universität Marburg/Ger Klug, R. Holländer, S. Lautenschläger and S. Geyler 2010: Renker, S. 2005: Luftbild Dirlammen. – Online available at: many Demographic change as a challenge to secure and develop https://upload.wikimedia.org/wikipedia/commons /7/70/Lautertal_Luftbildaufnahme_Dirlammen_Rengoo_

cost- and resource-efficient wastewater infrastructure. – HSL (Hessisches Statistisches Landesamt) (ed.) 2007-2012: Röske, I. and D. Uhlmann 2005: Biologie der Wasser- und Umweltbundesamt, Texte 36. – Dessau-Roßlau/Germany Sebastian_Renker_20050706.jpg, accessed 01/02/2016

Strukturdaten aus Bevölkerung und Wirtschaft. Hessi- RP Gießen (Regierungspräsidium Gießen) 2008: Begutachtung Hessische Gemeindestatistik 2006-2011. Ausgewählte Abwasserbehandlung. – Stuttgart/Germany

HVBG (Hessische Verwaltung für Bodenmanagement und sches Statistisches Landesamt. – Wiesbaden/Germany Abwassereinleitung der Kläranlage Dirlammen in das Geoinformation) 2017: TK 25 Hessen (CD) RPGI (Regierungspräsidium Gießen) 2017: Abwasser-, Trink- Brenderwasser am 05.08.2008. – Gießen/Germany IINAS (Internationales Institut für Nachhaltigkeitsanalysen wasser- und Niederschlagswassergebühren. – Regie- und -strategien) 2018: GEMIS - Globales Emissions-Modell vom 18.12.2017 rungspräsidium Gießen. Nicht veröffentlichte Mitteilung org/gemis-de.html, accessed 22/08/2018 Schmitz, S. and I. Paulini integrierter Systeme. – Online available at: http://iinas. IKEK 2013: Integriertes kommunales Entwicklungskonzept – Methode des Umweltbundesamtes zur Normierung 1999: Bewertung in Ökobilanzen von Wirkungsindikatoren, Ordnung (Rangbildung) von Wirkungskategorien und zur Auswertung nach ISO der Gemeinde Lautertal (Vogelsberg). – Lautertal/ Kessler, P. 2004: Germany Steuerungsmechanismen der Politik. – Marburger Geo- Schnell, R. 1999: Methoden der empirischen Sozialforschung. Wassernutzung und Gewässerschutz – 14042 und 14043. UBA-Texte 92/99. – Berlin/Germany graphische Schriften 140: 134-141 Klee, O Schubert, J. – München/Germany Klöpfer, W. and B. Grahl 2009: Ein Leitfaden für . 1998: Wasser untersuchen. – Wiesbaden/Germany 2006: Aussagefähigkeiten von Ökobilanzen. Ausbildung und Beruf. – Weinheim/ Rahmen der ökologischen Bewertung an Beispielen der Sensitivitätsanalyse der Wirkungsabschätzung im doi:10.1002/9783527627158 G e r m a n y , LAWA-AO (Landesarbeitsgemeinschaft Wasser-Ausschuss Forum Siedlungswasserwirtschaft und Abfallwirtschaft Klärschlammentsorgung in Nordrhein-Westfalen. –

196 DIE ERDE · Vol. 149 · 2-3/2018 Ecological, socio-economic and demographic analyses as prerequisites for sewage treatment problem solutions in rural areas. The case study of Dirlammen, Vogelsberg, Germany

accessed 05/12/2017 Seeger, H. UBA (Umweltbundesamt) Universität Duisburg-Essen. – Aachen/Germany treatment. – European Water Management 2: 51-56 available at: https://www.umweltbundesamt.de/daten/ 1999: The history of German waste water 2015: Fließgewässer. – Online Theilen, U., P. Jahnen and M. Heß 2014: Strategien zur 05/12/2017 WeKoDe (Wegweiser Kommune) 2017: – Online available wasser/fliessgewaesser, accessed at: https://www.wegweiser-kommune.de/kommunen/ Anpassung der Abwasserinfrastruktur bei rückläufigen der Abwasserentsorgung am Beispiel der Ortsteile lauterbach-hessen, accessed 09/11/2017 Bevölkerungszahlen im ländlichen Raum. Alternativen Dirlammen und Eichelhain der Gemeinde Lautertal WTW 2016: – Online available at: http://www.wtw.com/ de/produkte/produktklassen/tragbare-messgeraete/ taschenmessgeraete.html, accessed 21/01/2016 (Vogelsberg). – Online available at: https://www. 11-30-Anhang-Strategien-Dirlammen-Eichelhain.pdf, lautertal-vogelsberg.de/fileadmin/uploads/pdf/2014-

DIE ERDE · Vol. 149 · 2-3/2018 197