Algorithm 1c. UWWTP: Treatment Required (Catchment of Sensitive Areas)

Overview

Determine the nutrient requirements for a plant based on the nitrogen and phosphorus flags for the If receiving area (Eutrophication: rcaANitro, rcaAPhos; Quality of water for drinking: rcaB)

Inputs:

• rcaANitro → Does the primary If receiving area demand Nitrogen?

• rcaAPhos → Does it demand Phosphorus?

• rcaB → Secondary Nitrogen demand.

Simplified Logic

1. Check Article 5(4)

• If it applies, the result is automatically “Secondary” and exit leaf “01-C-07”.

• If it does not apply, we proceed to check nutrient demands.

2. Check primary Nitrogen (rcaANitro)

• If rcaANitro = 1:

  • If rcaAPhos = 1:

    • Required = (aN+aP)

    • Exit = 01-C-01

  • Else:

    • Required = (aN)

    • Exit = 01-C-02

• If rcaANitro = 0:

  • Use combinations of rcaB and rcaAPhos to determine:

    • rcaB = 0 & rcaAPhos = 0 → Secondary, 01-C-03

    • rcaB = 0 & rcaAPhos = 1 → (aP), 01-C-04

    • rcaB = 1 & rcaAPhos = 0 → (b), 01-C-05

    • rcaB = 1 & rcaAPhos = 1 → (aP+b), 01-C-06

Decision Tree

        graph TB
CSA["CSA"] --> ART["Article 5(4) applies"]

ART --- Y1((YES)) --- SEC["Required = Secondary"]
SEC -.- ID07(["01-C-07"])

ART --- N1((NO)) --- NAN["If receiving area demands Nitrogen (aN)"]

NAN --- Y2((YES)) --- PAP1["If receiving area demands Phosphorus (aP)"]
NAN --- N2((NO)) --- NB["If receiving area demands Nitrogen (b)"]

%% aN = YES branch
PAP1 --- Y3((YES)) --- NAP["Required = Nitrogen(a) & Phosphorus (aN + aP)"]
NAP -.- ID01(["01-C-01"])

PAP1 --- N3((NO)) --- NA["Required = Nitrogen(a) (aN)"]
NA -.- ID02(["01-C-02"])

%% aN = NO branch (Nitrogen b)
NB --- Y4((YES)) --- PAP2["If receiving area demands Phosphorus (aP)"]
NB --- N4((NO)) --- PAP3["If receiving area demands Phosphorus (aP)"]

%% Nitrogen b = YES branch
PAP2 --- Y5((YES)) --- NBP["Required = Nitrogen(b) & Phosphorus (b+aP)"]
NBP -.- ID06(["01-C-06"])

PAP2 --- N5((NO)) --- NBONLY["Required = Nitrogen (b)"]
NBONLY -.- ID05(["01-C-05"])

%% Nitrogen b = NO branch
PAP3 --- Y6((YES)) --- PONLY["Required = Phosphorus (aP)"]
PONLY -.- ID04(["01-C-04"])

PAP3 --- N6((NO)) --- SEC2["Required = Secondary"]
SEC2 -.- ID03(["01-C-03"])

classDef reference stroke:#00a2ff,color:#00a2ff;
class ID07,ID01,ID02,ID06,ID05,ID04,ID03 reference;

%% Styles
classDef reference stroke:#00a2ff,color:#00a2ff;
classDef yesBox fill:#4CAF50,color:white,stroke:#2E7D32;
classDef noBox fill:#F44336,color:white,stroke:#C62828;

%% Class Assignments
class ID07,ID01,ID02,ID06,ID05,ID04,ID03 reference;
class Y1,Y2,Y3,Y4,Y5,Y6 yesBox;
class N1,N2,N3,N4,N5,N6 noBox;
    

Pseudocode

Show python code

if article_5_4_applies: 
    result_required = "Secondary" 
    exit_leaf = "01-C-07" 

else: 
    if rcaANitro == 1: 
        if rcaAPhos == 1: 
            result_required = "(aN+aP)" 
            exit_leaf = "01-C-01" 

        else: 
            result_required = "(aN)" 
            exit_leaf = "01-C-02" 
    else: 
        if rcaB == 0 and rcaAPhos == 0: 
            result_required = "Secondary" 
            exit_leaf = "01-C-03" 

        elif rcaB == 0 and rcaAPhos == 1: 
            result_required = "(aP)" 
            exit_leaf = "01-C-04" 
            
        elif rcaB == 1 and rcaAPhos == 0: 
            result_required = "(b)" 
            exit_leaf = "01-C-05" 
            
        elif rcaB == 1 and rcaAPhos == 1: 
            result_required = "(aP+b)" 
            exit_leaf = "01-C-06"